How to reduce processor voltage on a laptop. Reducing the operating voltage of the processor, or tuning Enhanced Intel SpeedStep

It often happens that the laptop is strongly heated during the work. Sometimes this heating can lead not only to unpleasant feelings (well, not everyone is nice to work with a hot laptop) but also to freezes or to "blue screens of death".

This option, not only requires certain skills and knowledge of the user, but also can deprive the laptop warranty. How to do this is described in this material: Processor replacement - reduce processor supply voltage. This method is the easiest and most effective. It allows you to lower the temperature by 10-30 degrees.

As we see, the most optimal solution of the heating problem is to reduce the supply voltage of the processor. I will explain in what its essence: the amount of heat released by the processor is proportional to the square of supply voltage. Therefore, a relatively slight decrease in supply voltage can lead to a significant decrease in heat dissipation and power consumption. To illustrate this, I propose to get acquainted with the results of the study:

Core 2 DUO T7300 2.0 GHZ1.00B

Core 2 DUO T7300 2.0 GHZ1.25B

At these two screenshots, the maximum temperature of the Core 2 Duo T7300 processor, which is installed in laptop Acer. ASPIRE 5920G, after a thirty-minute "warmer" utility S & M. In the first case, the processor operated on the supply voltage of 1.25V, and in the second voltage of 1.00V. Sleeve comments. The difference in the maximum temperatures is 24 degrees and this is considering that in the first case the fan of the cooling system of the laptop worked on the maximum turnover and during the test, the processor protection has been triggered from overheating (this is visible on the temperature jump due to an emergency stop of the S & M utility)

In the circles of laptop users there is an erroneous opinion that with a decrease in the supply voltage of the processor, performance decreases. I will explain why this opinion is wrong. Performance is primarily determined by the frequency of the processor. Information processing occurs on each processor tact. The frequency is higher - the more clocks per second, therefore, the more information processor processes throughout the second. The supply voltage does not appear here. The processor supply voltage affects mainly the stability of the processor operation at a certain frequency. If you enhance it, the maximum frequency increases on which the processor works. This is how overclockers do. But there is also the reverse side of the medal: with an increase in the supply voltage of the processor, as mentioned above, its heat dissipation increases. That's what overclockers use powerful and complex cooling systems.

Now you can proceed directly to a decrease in processor supply voltage. For this we need a utility. You can download it on one of these links: (GContent) Download RMClock (/ GContent)

For a 64-bit Windows Vista, there is a problem with a digital signature for the RTCore64.sys driver. To avoid a similar problem - download the version of RMClock with an already certified driver on this link: (GContent) Download (/ GContent)

It does not know how to control the frequency and voltage of Intel Celeron M processors due to the fact that they do not support the dynamic frequency / voltage change (Intel Enhanced Speed \u200b\u200bStep technology in Intel Celeron M processors - is disabled. We say "Thank you" for this cap of Intel "Y). Also RMClock does not support new AMD processors (on 780G chipsets and older) and Intel Core i3, i5, i7 and other of the same family

Simplified configuration of this utility for users who have no time / desire / experience it is finely customized.

Expanded description of the configuration of this utility for users who want to achieve maximum efficiency of its work.

Note: In this material, the setting is made in Windows XP. The configuration procedure in Windows Vista is the same, with the exception of several nuances, which is described in this material: solving problems with reboots and laptop freezes

Simplified setup RMClock

Let's start with the launch of the utility. Go to the tab Settings And set the parameters as in the screenshot:

On this tab, we included the utility autoload. Go to next tab: Management. Configure as shown in the screenshot:

It is worth noting that a tick near the item OS POWER MANAGEMENT INTEGRATION First you need to remove, and then put again
Go to the tab Advanced CPU Settings. If you have a processor from Intel Configure as in the screenshot below:

It is very important that a daw stay near the item Mobile. The remaining items can be inactive. We do not pay attention to it

For processors OT. AMD. Tab Advanced CPU Settings Must have this kind:

Now go to the most interesting thing - to the tab Profiles. For processors Intel It may have this kind:

If you have a tick near the item IDA. - Remove it

Note: What we removed there a checkbox still does not mean that Ida technology will not work. She will work. Just in this case will be less glitches

Now I will explain how to put stresses. For the highest multiplier (not counting IDA.) We put a voltage of 1.1000V. In my case, this multiplier - 10.0x. On this voltage is able to work the overwhelming majority of processors Core 2 duo.. If your laptop freezes after applying settings - it means that this voltage should be increased to 1.1500V. For the highest multiplier, we put the voltage of 0.8000-0.8500v. The utility itself puts the intermediate values. With such settings, when working on the network, the laptop will operate at the maximum frequency, and when switching to power from batteries - on the minimum for better energy saving.

ATTENTION: In no case do not put the voltages above 1.4000V !!!

For laptops on processors from AMD. This tab will have this kind:

Here for the greatest multiplier (in my case it is 10.0x) we put the voltage of 1.0000V. For the smallest - the smallest value that allows you to set the utility.

Note: If you put a very small voltage, then it does not mean that the processor will work on it. The thing is that the minimum voltage on which the processor can work is rigidly set for each individual processor. If you put in RMClock low voltage, The processor will result in minimal voltage, which allows you to set the motherboard.

Go directly to the profile settings, in particular Power Saving..

For processors Intel It has this kind:

For processors AMD. She looks like this:

Here we put ticks near the top points. Go to the tab Maximal Performance..

For processors Intel It has this kind:

For processors AMD. It has this kind:

On this tab, we put ticks near the lowest points with the highest multipliers.
To RMClock does not have conflicts with Windows XP. - We go to the properties: Power Supply (Start -\u003e Control Panel -\u003e Power Supply) and select the profile profile in the selection window Rmclock Power Management and click OK.

Note: You don't need to do this for Windows Vista.

To view what voltage and frequency processor is running - go to the tab Monitoring

As you can see, the processor in my case operates at a frequency of 2000 MHz, on a multiplier 10.0 and at a voltage of 1.100 V. Its temperature is 45 degrees.

Here, perhaps, everything. If you want to deeper to deal with this utility - read on

Full Description RMClock Settings

In this part, I will tell you more detail about the settings of the utility itself. Let's start with the consideration of the tab Settings

I will describe what is on this tab. At the top, the window is placed to select the program language. To select the Russian language you need to download the appropriate .dll library (which else needs to be found ...)

Below are these settings:

Colors. - Color settings for monitoring windows.
Show Informational Balloon Tooltips - Show information pop-up tips in the tray
Show Critical Balloon Tooltips - show critical messages in the tray, with overheating, for example
Make Application Window Always On Top - Position the application window over other windows
Show Application Button in Taskbar - Show application button in Tasquebar
Temperature Units. - Temperature measurement units (degrees Celsius / Fahrenheit)

Even below are autorun options:

Start Minimized To System Tray - run rolled into the system tray (near the clock)
RUN AT Windows Startup - Run when Windows startup. On the left you can choose ways of autorun: using the registry key or through the folder

And at the bottom, the logging options are configured. What and how to monitor.

On the tab CPU info You can find more information about the processor.

View of this tab for platforms based on Intel And on the base AMD. May be completely different. First I will describe for the platform Intel:

At the very top there are 3 tabs. Processor., ChipSet. and Throttling. Tabs ChipSet. and Throttling It does not imagine much practical interest for us, because they do not touch them and leave the default parameters. But on the tab Processor. Let us dwell.
At the top under the inscription Automatic Thermal Protection. 4 points are posted:

Enable Thermal Monitor 1 - Enable TM1.
Enable Thermal Monitor 2 - Enable TM2.
Sync. TM1 ON CPU CORES - synchronize TM1 to the processor kernels
Enable Extended Throttling - Enabling extended trolling.
More detailed about what TM1. and TM2. We read in the documentation for the processor. There these all technologies are correctly described. In a nutshell: they serve to protect the processor from the failure due to overheating. If the processor temperature reaches a certain value (usually 94-96 s), the processor will switch to the mode that is specified to the right under the inscription Thermal Monitor 2 Target

In the window FID / VID TRANSITION STABILIZATION TIME The stabilization time is specified when moving from one mode of operation of the processor to another.

Below under the inscription Intel Core / Core 2 Family Enhanced Low Power States The various possible states of the processor with reduced power consumption are included. What C1E., C2E.... described in the same documentation for the processor. There it is filed in the form of a plate.

At the bottom of the tab Advanced CPU Settings There are 2 interesting items:

ENGAGE INTEL DYNAMIC ACCELERATION (IDA) IDA.. The essence of this technology is reduced to the fact that in processors with several nuclei at the moments when the load on one of them is high, it switches to a higher multiplier. That is, if for the processor T7300, the nominal multiplier X10, then in moments with a high load on one nucleus, it will work at a frequency of not 2.0 GHz, and by 2.2 GHz with a multiplier x11 instead of x10.
Enable Dynamic FSB Frequency Switching (DFFS) - This option includes technology DFFS.. Its essence comes down to the fact that to reduce the power consumption frequency system Tire decreases from 200 MHz to 100 MHz.

Just below, select the type of processor. In our case, it Mobile and put a tick near

Now let's see what the property will look like Advanced CPU Settings For processors based systems AMD.:

I will dwell only at the most important points.
Top again there are 3 tabs. We are interested in a greater extent tab CPU Setup.
Sleva in the window ACPI STATE TO View / MODIFY Select the profile (state) of the processor power consumption with which we will work on this tab.

Enable CPU Low Power - Enabling the energy saving processor mode
Enable NorthBridge Low Power - inclusion of the energy saving mode of the Northern Bridge
Enable FID / Vid Change - Enable the ability to change the voltage / multiplier
Enable Altvid Change. - include an opportunity for alternative voltage change
Apply These Settings at Startup - Apply these changes after booting OS.
If you press the triangles on the right of the inscription ACPI Power States Settings The menu will appear with presets.
There were more questions for what one or another checkbox - read the instructions for the program or as always - by the method of tyk

Now let's go to the tab Management

In a nutshell, I will explain why that or another check mark.

P-STATES TRANSITIONS METHOD: - In this window, you can set a way to transition from one P-state (in fact it is a combination of a certain value of the multiplier and voltage) to another. Two options are possible - one-step - single-step (that is, if the processor switches from the X6 multiplier to x8, then first it makes the X6-\u003e X7 transition, and then x7-\u003e x8) and multi-step - Multi-Step (with x6 immediately on x8 without transition to x7)
Multi-CPU Load Calculation - This window defines a method for determining the processor loading (for Performance ONDEnd mode, for example). In the screenshot, the method is specified when the download is equal to the maximum loading of any of the cores.
STANDBY / HIBERNATE ACTION - It is set to the action when switching to waiting mode or in hibernation mode. In the screenshot, the option "Leave the current profile"

The following is the default values \u200b\u200bof the processor - CPU DEFAULT SETTINGS
Restore CPU Defaults on Management Turns Off - renew the default values \u200b\u200bwhen you turn off the RMClock control
Restore CPU Defaults ON Application EXIT - Renew the default values \u200b\u200bwhen closing the RMClock utility

Just below the inscription CPU DEFEAULTS SELECTION You can choose one of three options:

CPU-DEFINED DEFAULT P-STATE - Voltage / multiplier by default are determined by the processor
P-STATE FOUND AT STARTUP - Voltage / multiplier by default are at the start of the OS
CUSTOM P-STATE - voltage / multiplier defaults are set manually

But on the tick Enable OS Power Management Integration It is worth paying special attention. It must be finished first, and then put again. After that, you need to go to Control Panel -\u003e Power Supply and select a "RMClock Power Management" power circuit. As an option - you can in the utility Acer Epower Select profile Rmclock Power Management. If this is not done, then conflicts between the OS and the utility are possible when they will simultaneously control the frequency and voltage of the processor. As a result, constant voltage and frequency jumps are possible.

Now go to the most interesting: voltage setting. The simplified setting shows the values \u200b\u200bthat the percentages of 90-95 users are suitable. But practice shows that often processors can work consistently on more-low voltages, which means even less heat dissipation and energy consumption, which is poured into reducing heating and increase the time autonomous work.

Note: Voltage setting is applied to the Intel Core 2 DUO processor. For other processors (including AMD products), the configuration procedure is the same. Just there will be other values, the number of multipliers and, naturally, voltages. Here I want to dispel another error. Often, users believe that if they have, for example, T7300, like me, then they will work on the same stresses as me. THIS IS NOT TRUE. Each individual instance has its own values \u200b\u200bof minimum stresses. That one percent specific model Works on a specific voltage does not mean that the other percent of the same model will work on the same voltage. In other words: if you put what screenshots are not the fact that it will work.

Now our task is to determine the minimum voltage values \u200b\u200bon which this processor will work consistently. For this we need the S & M utility (GContent) Download S & M (/ GContent)
Briefly describe the tab Profiles:

At the top of the tab there are 4 windows. I will explain why they are needed. In two windows on the left under AC Power currently exhibited ( Current) and booty ( Startup.) system profiles when nutrition of a laptop from the network, a little right Baterry.currently exhibited ( Current) and booty ( Startup.) System profiles when the laptop is nutrition from the battery. Profiles themselves are configured on the samples (just below Profiles). Below there is still a font - . It is responsible for autofilling voltages, that is, set the upper value on one multiplier, set the lower on the second, when the daws near that item was delivered, the program itself will set the intermediate values \u200b\u200bby linear interpolation.

As we can see in the screenshot, when working from the network, the laptop will work at frequency / voltage that are set in the profile Maximal Performance.and when the laptop will work from batteries - frequency and voltage will be set in the profile Power Saving.

Now proceed directly to the definition of minimum stresses in which the system is still stable. To do this, remove all the ticks, besides the one that is responsible for the highest multiplier (not counting IDA.). We put a voltage of 1.1000V, for example (for AMD. You can start with 1.0000V)

Go to the sampling Maximal Performance. (This profile is now active, the laptop is running from the network)

Celebrate our factor checkbox and launch S & M.. When you first start, this utility honestly warns us:

Click OK

Now go directly to setting up this utility. Go to the tab 0

We choose the test that the processor most is very much warms up. Then it does and on the tab 1 (the processor has two cores)

Now go to the tab Settings. First set the maximum processor load:

put the duration of testing on Long (about 30 minutes for Norm - 8 minutes) and turn off the memory test

and click on the button Start check

On the tab Monitor You can track the current processor temperature:

If during the time checking the laptop does not hurt, it did not reboot and did not give out the "blue screen" means it passed the test and the voltage can still be reduced. To do this, go to the tab Profiles and reduce the voltage 0.0500v:

Run a utility again S & M.. If this time everything went well - it means that you can still reduce the voltage ... If the testing passed unsuccessfully - the voltage should be increased. The goal is simple: to find a voltage at which the laptop will be tested to the utility S & M..
Ideally, it is necessary for each multiplier to find such a tension, but in order not to kill a lot of time - we put the maximum multiplier of the voltage that we have determined, put the minimum factor (in my case 6.0x) the minimum voltage that the motherboard may set the motherboard (as a rule , this is 0.8-0.9 c) ... And the intermediate values \u200b\u200bof the letters are filled with the function AUTO-ADJUST INTERMEDIATE STETES VIDS

In this utility there is another feature that I did not mention: this is a change in the frequency of the processor depending on the load.
In profiles Maximal Performance. and Power Saving. It is possible to choose only one processor frequency value with a specific voltage. If you need to organize flexible frequency management depending on the processor loading it is worth paying attention to the profile Performance on Demand.. It is different from Maximal Performance. and Power Saving. The fact that here you can specify one or more combinations of the voltage / multiplier on which the processor will work.
Here is an example of its settings:

At the bottom in the settings of this profile there are some parameters that we can change. In short, I will describe them:

Target CPU Usage LEVEL (%) - Specifies the multiplier / voltage shift threshold. The transition occurs only between those multipliers and stresses that are marked with ticks in the window above. The method of measuring the processor load is defined on the tab Management

Up Transition Interval - Determines the time during which the loading of the processor should be higher for the above threshold, to switch to a higher multiplier of the ticks marked above.

Down Transition Interval - Determines the time during which the processor load should be lower for the above threshold, to switch to a lower multiplier from the above checkboxes.

On the settings of each with profiles there are trolling options - Use Throttling (ODCM). I do not recommend it, because the frequency is reduced, and the heating increases. You can also specify the power supply parameters of the system (monitor disabling time, turns off) on the tab OS settings:

To activate profile Performance on Demand. - We must choose it in the windows Current On the tab Profiles

Here, perhaps, all.

In modern desktop and (especially) mobile processors, a number of energy-saving technologies are applied: ODCM, CXE, EIST, etc. Today we will be interested in, perhaps, the highest level of them: flexible control of the frequency and voltage of the processor core during operation - Cool "N "QUIET, POWERNOW! AMD and Enhanced Speedstep (EIST) at Intel.

Most often, the user of the computer or laptop is enough to simply turn on (put a tick) support for a particular technology in the BIOS and / or operating system - no fine setting is usually provided, although, as practice shows, it can be very useful. In this article, I will tell you how to control the operating voltage of the processor kernel from operating system (For example Intel Pentium. M and FreeBSD), and why it may be needed.

Despite the large number of manuals, rarely encounter a detailed description of the Enhanced SpeedStep technology from the point of view of the operating system (and not the end user), especially in Russian, therefore a significant part of the article is devoted to the details of the implementation and is somewhat theoretical nature.

I hope the article will be useful not only by FreeBSD users: we also slightly touch GNU / Linux, Windows and Mac OS X. However, in this case, the specific operating system has a secondary value.

Preface

Last year, I prohapgrrew a processor in my old laptop: put Pentium M 780 instead of a regular 735th, finished up to a maximum, so to speak. The laptop began to warm up under load (due to 10 W heat generation); I did not particularly add on this attention (unless it cleaned and smeared the cooler), but one day, during a long compilation, the computer ... just turned off (the temperature of the same reached critical hundred degrees). I brought the value of the system variable hw.acpi.thermal.tz0.temperature in the tray to watch the temperature and, if that, in time to interrupt the "heavy" task. But after some time I lost vigilance (the temperature always remained within the normal range), and everything happened. At this point, I decided that I no longer want to constantly fear the emergency shutdown during the long-term load of the CPU and keep the hand on Ctrl-C, nor random the processor.

Usually, the change in the standard voltage implies its increase in order to ensure stable operation of the processor during acceleration (i.e. at an increased frequency). Roughly speaking, each voltage value corresponds to some frequency range on which it can work, and the overclocker task is to find the maximum frequency on which the processor is not yet "buggy". In our case, the task is in a sense symmetric: for a known frequency (more precisely, as we will soon find out, the dialing of frequencies) find the smallest voltage that ensures the stable operation of the CPU. It does not want to lower the operating frequency so as not to lose in productivity - a laptop and so far from topic. Also lower voltage more profitable.

A bit of theory

As is known, the heat generation of the processor is proportional to its capacity, frequency and square Voltage (who is interested, why this can try to derive dependency on their own, considering the processor as a set of elementary CMOS-inverters (logical negatives), or go on the links: once, two, three).

Modern mobile processors May consume up to 50-70 W, which are eventually dissipated in heat. It is a lot (remember incandescent lamps), especially for a laptop that in offline mode Under the load will "eat" the battery like that pig oranges. In conditions of limited space, heat is likely to be actively, which means an additional energy consumption for the cooler fan rotation (possibly several).

Naturally, this state of affairs has not satisfied anyone, and processor manufacturers began to think about how to optimize power consumption (and, accordingly, heat transfer), and at the same time to prevent the processor from overheating. I recommend that I recommend to read a number of remarkable articles in Dmitry Besedin, and in the meantime I will go directly to business.

A bit of history

For the first time, SPEEDSTEP technology (version 1.1) appeared in the second generation of third pentiums (produced by 10 microns Mobile CopperMine Mobile CopperMine, 2000), which, depending on the load or power source, a network or battery - could switch between high and low frequencies due to a variable multiplier. In economical mode, the processor consumed about twice as much as the energy.

With the transition of a.13 μM technical process technology receives version 2.1 number and becomes an "enhanced" (enhanced) - now the processor can lower not only frequency, but also voltage. Version 2.2 - Adaptation for the NetBurst architecture, and to the third version (CENTRINO platform), the technology will be officially called Enhanced Intel Speedstep (EIST).

Version 3.1 (2003) is first used in the first and second generations of Pentium M processors (Banias and Dothan kernels). The frequency varied (first - only switched between two values) from 40% to 100% of the basic, in 100 MHz (for Banias) or 133 MHz (for Dothan, our case). At the same time, Intel introduces the dynamic control of the tank of the second level cache (L2), which makes it even better to optimize power consumption. Version 3.2 (Enhanced EIST) - Adaptation for multi-core processors with shared L2 cache. (Small FAQ from Intel using SpeedStep technology.)

Now, instead of blindly follow the numerous HOWTO and tutorials, download PDF "KU and try to figure out in principle EST (I will continue to use this abbreviation, because it is universal and shorter).

How EST works

So, EST allows you to manage the performance and power consumption of the processor, and dynamically, during his work. Unlike earlier implementations that required hardware support (in the chipset) to change the processor operating parameters, EST allows software. The BIOS or operating system, change the multiplier (processor frequency ratio to the tire frequency) and the kernel voltage (V CC), depending on the load, the type of computer power supply, the temperature mode CPU and / or settings (policies) of the OS.

During operation, the processor is in one of several states (Power States): T (Throttle), S (Sleep), C (IDLE), P (Performance), switching between them according to a specific rules (p. 386 ACPI 5.0 specifications).

Each processor present in the system must be described in the DSDT table, most often in the namespace \\ _pr, and usually provides a number of methods through which interaction with the operating system (PM driver) occurs, and which describe the processor capabilities (_PDC, _PPC) Supported states (_CST, _TSS, _PSS) and control them (_ptc, _pct). The desired values \u200b\u200bfor each CPU (if it is included in the so-called CPU Support Package) is defined by the BIOS of the Motherboard, which fills the corresponding tables and ACPI methods (pdf "ki) when loading the machine.

EST manages the work of the processor in the P-state (P-State), they will be interested in us. For example, Pentium M supports six P states (see Fig. 1.1 and tab. 1.6 PDF "KI), characterized by voltage and frequency:

In general, when the processor is unknown in advance, the only more or less reliable (and recommended Intel) using it is ACPI. You can interact with a specific processor directly, bypassing ACPI, - through the MSR registers (Model-Specific Register), including directly from command line: Starting with version 7.2, in FreeBSD it uses the Cpucontrol utility (8).

To find out if your EST processor supports, you can look at the 16th bit in the IA_32_MISC_ENABLE register (0x1a0), it must be set:

# KLDLOAD CPUCTL # Cpucontrol -m 0x1a0 / dev / cpuctl0 | (read _ MSR Hi Lo; Echo $ ((Lo \u003e\u003e 16 & 1))) 1
A similar command for GNU / Linux (the MSR-Tools package will be required):

# MODPROBE MSR # Echo $ ((`rdmsr -c 0x1a0` \u003e\u003e 16 & 1)) 1
The transition between states occurs when writing to the IA32_PERF_CTL register (0x199). You can find out the current mode of operation, you can read the IA32_Perf_Status register (0x198), which is updated dynamically (Tab. 1.4 PDF "KI). In the future, the prefix IA32_ I will be omitted for brevity.

# Cpucontrol -m 0x198 / Dev / CPUCTL0 MSR 0x198: 0x0612112b 0x06000c20
From the documentation it follows that the current state is encoded in the lower 16 bits (if you execute the command several times, their value may vary - this means that EST works). If you look more carefully for the rest of the bits, they are also clearly not trash in them. Google, can find out what they mean.

PERF_STATUS register register

The data read from Perf_status seems to be the following structure (we assume that the data is stored as Little-Endian):

STRUCT MSR_PERF_STATUS (Unsigned Curr_psv: 16; / * Current PSV * / unsigned status: 8; / * Status Flags * / unsigned min_mult: 8; / * Minimum Multiplier * / unsigned max_psv: 16; / * maximum PSV * / unsigned init_psv: 16; / * Power-ON PSV * /);
Three 16-bit fields are the so-called Performance State Values \u200b\u200b(PSV), their structure we will look below: The current PSV value, maximum (depends on the processor) and the value at the start of the system (when turned on). The current value (Curr_psv) is obviously changing when the operation mode changes, the maximum (max_psv) is usually constant, the starting value (init_psv) does not change: as a rule, it is equal to the maximum value for desktops and servers, but minimal for mobile CPUs. The minimum multiplier (min_mult) for Intel processors is almost always equal to six. The Status field contains the value of some flags, for example, when EST or THERM events occurs (i.e., at the time of changing the P state or overheating of the processor, respectively).

Now that we know the purpose of all 64 bits of the perf_status register, we can decipher the word read above: 0x0612 112b 0x06 00 0C20 ⇒ PSV At start 0x0612, the maximum value of 0x112b, the minimum multiplier 6 (as expected), the flags are reset, the current value is PSV \u003d 0x0c20. What exactly do these 16 bits mean?

PERFORMANCE STATE VALUE (PSV)

To know and understand that the PSV is, it is very important, because it is precisely in this form that the modes of operation of the processor are set.

Struct PSV (unsigned vid: 6; / * Voltage Identifier * / unsigned _reserved1: 2; unsigned freq: 5; / * Frequency Identifier * / unsigned _reserved2: 1; unsigned NIBR: 1; / * Non-Integer Bus Ratio * / unsigned SLFM: 1; / * Dynamic FSB Frequency (Super-LFM) * /);
Dynamic FSB Frequency Switching Specifies to skip every second FSB clock, i.e. twice the operating frequency; This feature is first implemented in the Core 2 Duo processors (Merom core) and we do not concern, like Non-Integer Bus Ratio - special regimeSupported by some processors, allowing, as follows from the name, is more subtly controlled by their frequency.

The EST actually has a relationship of two fields - frequency identifiers (Frequency Identifier, FID), which is numerically equal to the multiplier, and voltage (Voltage Identifier, VID), which corresponds to the voltage level (it is usually and least documented).

Voltage ID (VOLTAGE IDENTFIER)

Intel quite reluctantly discloses information (usually need to sign NDA) about how the voltage identifier is encoded for each processor. But for most popular CPUs, fortunately, this formula is known; In particular, for our Pentium M (and many others): V Cc \u003d Vid 0 + (VID × V STEP), where V Cc is the current (valid) voltage, VID 0 is the base voltage (when Vid \u003d\u003d 0), V Step - step. Table for some popular processors (all values \u200b\u200bin millivolts):

CPU	Vid 0.	V Step.	V boot	V min	V Max
Pentium M.	700,0	16,0	xXXX, X.	xXX, X.	xXXX, X.
E6000, E4000	825,0	12,5	1100,0	850,0	1500,0
E8000, E7000	825,0	12,5	1100,0	850,0	1362,5
X9000.	712,5	12,5	1200,0	800,0	1325,0
T9000.	712,5	12,5	1200,0	750,0	1300,0
P9000, P8000	712,5	12,5	1200,0	750,0	1300,0
Q9000D, Q8000D.	825,0	12,5	1100,0	850,0	1362,5
Q9000m.	712,5	12,5	1200,0	850,0	1300,0

The multiplier (i.e. fid) is recorded in the PSV shifted to 8 bits left, the younger six bits takes VID. Because In our case, the rest of the bits can be neglected, then PSV, the frequency of the processor, the system tire and physical voltage are associated with a simple formula (for Pentium M):
Now consider the control register (PERF_CTL). The entry should be recorded as follows: first reads the current value (64-bit word entirely), it changes the necessary bits, and writes back to the register (so-called Read-modify-write).

PERF_CTL register structure

struct msr_perf_ctl (unsigned psv: 16; / * Requested PSV * / unsigned _reserved1: 16; unsigned iDa_Diseng: 1; / * IDA DiseGage * / unsigned _reserved2: 31;);
Ida (Intel Dynamic Acceleration) Disengage-bit allows you to temporarily disable the adaptive (Opportunistic) frequency control on the Intel Core 2 Duo T7700 processors and later, - again, we are not interested. Junior 16 bits (PSV) - the mode in which we "ask" to switch the processor.

Table _PSS

Table _SSS is an array of states ( Package. in ACPI terminology) or a method that returns such an array; Each state (p-state) in turn is determined by the following structure (p. 409 ACPI specifications):

Struct PSTATE (unsigned corefrequency; / * Core CPU Operating Frequency, MHz * / Unsigned Power; / * Maximum Power Dissipation, MW * / unsigned Latency; / * Worst-Case Latency of CPU Unavailability During Transition, μs * / unsigned busmasterlate; / * Worst-Case Latency While Bus Masters Are Unable to Access Memory, μs * / unsigned control; / * Value to Be Written to the Perf_ctl to Switch to this State * / unsigned status; / * Value (SHOLD BE EQUAL TO THE ONE READ from perf_status) * /);
Thus, each P-state is characterized by some kind of operating system of the kernel, the maximum dispel power, transit delays (in fact, this time of transition between states, during which the CPU and memory are not available), finally, the most interesting: PSV, which corresponds to this state and Which should be written in Perf_ctl to go to this state (Control). To make sure that the processor has successfully switched to a new state, you need to read the perf_status register and compare with the value recorded in the Status field.

The operating system EST driver can "know" about some processors, i.e. We will be able to manage and without ACPI support. But this is a rarity, especially today (although for undervolting "and on Linux, somewhere to version 2.6.20, it was necessary to patch the tables in the driver, and in 2011 this method was very common).

It is worth noting that the EST driver can work even in the absence of a table _ss and an unknown processor, because Maximum and minimum values \u200b\u200bcan be found from Perf_status (in this case, obviously, the number of P states is degenerated into two).

Pretty theories. What to do with it?

Now, when we know 1) assigning all the bits in the necessary words MSR, 2) how exactly the PSV is encoded for our processor, and 3) where in DSDT to seek need settings, it's time to make a table of frequencies and voltages default. I'll dismiss DSDT and look for the _PSS table there. For Pentium M 780, it should look something like this:

Default _PSS Values.

Name (_SSS, Package (0x06) (// Total 6 states (P-STATES) Package (0x06) (0x000008db, // 2267 MHz (CF. FID × FSB Clock) 0x00006978, // 27000 MW 0x0000000a, // 10 μs (complies with the specifications) 0x0000000a, // 10 μs 0x0000112b, // 0x11 \u003d 17 (multiplier, fid), 0x2b \u003d 43 (VID) 0x0000112b), package (0x06) (0x0000074b, // 1867 MHz (82% of the maximum) 0x000059d8, // 23000 MW 0x0000000a, 0x0000000a, 0x00000e25, // FID \u003d 14, VID \u003d 37 0x00000e25), package (0x06) (0x00000640, // 1600 MHz (71% of the maximum) 0x00005208, // 21000 MW 0x0000000a, 0x0000000a 0x00000C20, // FID \u003d 12, VID \u003d 32 0x00000C20), Package (0x06) (0x00000535, // 1333 MHz (59% of the maximum) 0x00004650, // 18000 MW 0x0000000a, 0x0000000a, 0x00000a1c, // FID \u003d 10, Vid \u003d 28 0x00000a1c), Package (0x06) (0x0000042b, // 1067 MHz (47% of the maximum) 0x00003E80, // 16000 MW 0x0000000a, 0x0000000a, 0x00000817, // FID \u003d 8, VID \u003d 23 0x00000817), package (0x06 ) (0x0. 0000320, // 800 MHz (35% of the maximum) 0x000032c8, // 13000 mw 0x0000000a, 0x0000000a, 0x00000612, // FID \u003d 6, Vid \u003d 18 0x00000612)))

So, we know default Vid for each P-level: 43, 37, 32, 28, 23, 18, which corresponds to voltages from 1388 mV to 988 mV. The essence of undervolting "But that certainly these voltages are somewhat higher than it is really necessary for the steady operation of the processor. Let's try to determine the" boundaries of the pervolored ".

I wrote a simple shell script for this, which gradually lowers the VID and performs a simple cycle (the PowerD (8) daemon (8) before that, of course, must be killed). Thus, I determined the voltages that allow the processor at least not to hang, then drove the Super PI test and rebuilding the kernel several times; Already later, I raised the VID value for two maximum frequencies for another point, otherwise the GCC occasionally departed due to an Illegal Instruction error. As a result of all experiments, for several days, such a set of "stable" VID: 30, 18, 12, 7, 2, 0 was obtained.

Analysis of the results

Now that we empirically identified the minimum safe voltages, it is interesting to compare them with source:
A decrease in the maximum voltage even brought quite tangible results by 15%: a long load not only does not lead more to overheating of the processor and emergency disconnection, the temperature now almost never exceeds 80 ° C. The predicted battery life in the "office" mode, judging by ACPICONF -I 0, increased from 1 h. 40 m. Up to 2 h. 25 m. (Not so much as much, but lithium-ion elements with time "tired", And I did not change the battery from the moment of buying a laptop seven years ago.)

Now it is necessary to make the settings apply automatically. You can, for example, modify the CPUFREQ (4) driver so that the PSV values \u200b\u200bare taken from their own table, and not through ACPI. But it is uncomfortable at least that you need to not forget the patches of the driver when updating the system, and indeed - more like a dirty hack than on the solution. It is possible, probably somehow to disappear POWERD (8), which is bad about the same reasons. You can simply run the script, lowering the voltage of the direct record in the MSR (which, in fact, I did to determine the "stable" voltages), but then you have to remember about and independently process the transitions between states (not only P-states, in general, by any, for example, When the laptop is out of sleep). No matter.

If we get PSV values \u200b\u200bvia ACPI, then the logical to change the Table _SS to DSDT. Fortunately, the BIOS does not have to pick for this: FreeBSD is able to upload a DSDT from the file (about the modification of the ACPI tables on Habré already, so we will not stop in detail now). We replace the desired fields in DSDT:

Undervolting Patch for _PSS

@@ -7385,8 +7385.8 @@x00006978, 0x0000000a, 0x0000000a, - 0x0000112b, - 0x0000112b + 0x0000111d, + 0x0000111d), Package (0x06) @@ -7395,8 +7395.8 @@x000059d8, 0x0000000a, 0x0000000a, - 0x00000e25, - 0x00000e25 + 0x00000e12, + 0x00000e12), Package (0x06) @@ -7405.8 +7405.8 @ 0x00005208, 0x0000000a, 0x0000000a, - 0x00000c20, - 0x00000c20 + 0x00000c0c, + 0x00000c0c), package ( 0x06) @@ -7415,8 +7415.8 @ 0x00004650, 0x0000000a, 0x0000000a, - 0x00000a1c, - 0x00000a1c + 0x00000a07, + 0x00000a07), Package (0x06) @@ -7425.8 +7425.8 @ 0x00003E80, 0x0000000a, 0x0000000a, - 0x00000817, - 0x00000817 + 0x00000802, + 0x00000802), Package (0x06) @@ -7435,8 +7435,8 @ 0x000032c8, 0x0000000a, 0x0000000a, - 0x00000612, - 0x00000612 + 0x00000600, + 0x00000600) )

Complete the new AML file (ACPI bytecode) and modify /Boot/loader.conf so that FreeBSD loaded our modified DSDT instead of default:

ACPI_DSDT_LOAD \u003d "YES" ACPI_DSDT_NAME \u003d "/ ROOT / UnderVolt.aml"
Here, in general, all. The only thing, do not forget to comment on these two lines in /Boot/loader.conf, if you change the processor.

Even if you are not going to lower regular voltages, the ability to customize the control of the state of the processor (not only P-states) can be useful. After all, it often happens that the "curve" BIOS fills the tables incorrectly, not completely, or does not fill them at all (for example, because it is not supporting Est Cherlene, and the manufacturer does not officially provide its replacement). In this case, you will have to do all the work on your own. Please note that adding one only to the _SSS table may not be enough; Thus, the C-STATES is set by the _cst table, and in addition, it may be necessary to describe the control procedures themselves (Performance Control, _PCT). Fortunately, it is easy and quite detailed, with examples, described in the eighth chapter of the ACPI specification.

Undervolting in GNU / Linux

In truth, at first I thought it would be enough for me to read Gentoo Undervolting Guide and simply adapt it for FreeBSD. It turned out not so simple, because the document on verification was extremely stupid (which is generally strange for Gentoo Wiki). Unfortunately, on their new site I didn't find anything like, I had to be content with an old copy; And although I understand that this leadership lost a lot of relevance, I still a little abstract it. :-)

For some reason, I immediately, without the announcement of the war, is offered to patt the kernel (in FreeBSD, for a minute, we are generally no systematic the code I did not have to modify). To score in the inside of the driver or write to some init-scripts, the values \u200b\u200bof some "safe" voltages are incomprehensible to whom and how the resulting, from a special table (in which Pentium M 780 is a rowing line consisting of some question characters). Follow the advice, among which there are written people who are clearly not understood at all what they are talking about. And most importantly, it is completely unclear why and how exactly these magical replacements of some numbers to others work; It is not proposed to "touch" EST, before something patches and reoper the kernel, the MSR registers are never mentioned and work with them from the command line. The modification of ACPI tables is not considered as an alternative and more preferred option.

The macro interacts quite tightly with (and calculates on the correct operation) ACPI, and the modification of the tables is one of the main methods of its adjustment for a specific iron. Therefore, the first thing that comes to the head is - in the same way to dare to disappear your DSDT. Alternative method: Google: //intelenhancedSpeedstep.kext, for example, once, two, three.

Another "wonderful" utility (fortunately, already outdated) offers to buy for $ 10 the ability to change the voltage and frequency. :-)

Introduction
For a long time I wanted to dwell on issues power consumption Modern personal computers and laptops. Many users will justify the question: "Why is it necessary? - The manufacturer has already taken care of all the subtleties of energy consumption of my system. As experience shows, unfortunately, it is almost always wrong. If the manufacturers of laptops are still trying to reduce the power consumption of their devices somehow, With personal computers, as a rule, everything is in the started state.

Power consumption of personal computers And it is necessary to reduce for the following reasons:
- reducing the power consumption of the laptop, you extend its battery life,
- extended battery life of the laptop, you achieve, reducing the charge / discharge cycles of the battery and extend its service life,
- The heat generation of the components of the laptop or personal computer is reduced with power consumption, which allows, on the one hand, to increase the stability of the system, on the other hand, extend the service life of electrical components,
- Reducing the power consumption of a personal computer and a laptop will reduce electricity costs. For many, it is still not critical, but the cost of electricity is growing day by day, state policy makes citizens establish electricity meters, the number of computers in the family increases from year to year, the duration of their work is lengthened in a proportional scale, therefore, in the technology of reduction of power consumption, each of us.

Determining key components of the power consumption of the system.

Despite the fact that modern personal Computer and notebook So different among themselves, as a rule, they are completely identical according to the schemes of the structure. In a laptop, manufacturers try to compose everything, so to reduce the final dimensions. While any personal computer is a modular system, any component of which can be replaced without any problems.

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The presented drawing shows the components standard system Block . Knowledge of these components of the system will allow you on the assembly stages or upgrade your computer to determine the parameters that will reduce the power consumption of the system. So, the modern system unit contains:
- body,
- Power Supply,
- motherboard,

RAM,
- video card / video cards,
- hard drive / discs,
- CD-drive,
- drives,
- Cartriders,
- processor cooling systems, housing.
Sound cards, TV tuners in a separate version are rarely found in modern computers. First, all existing motherboards have built-in sound controllers, which are not inferior in terms of sound quality cheap sound cards and medium price range cards. Secondly, TV tuners served as coaxial television. In the era of Fulhd, IP-TV, DVB speaks about TV tuners simply too unnecessary.

Energy saving: body and power supply.

For many it may seem strange, discuss the power supply and housing In the context of energy-saving technologies. Nevertheless, practice shows that users often choose the case by appearance and its price parameter. It should be understood that a small-sized, poorly ventilated body will contribute to overheating the components of the system and reduce the stability of the same processor, RAM, motherboard with a decrease in supply voltages, which we will continue.

Power Supply It can become a source of inefficient power consumption in the first place. Any modern power supply must provide high efficiency indicators when converting high voltage current at 12, 5 and 3.3 volts.

Any modern power supply has compliance with one of the standards of the series. 80 Plus.. The 80 PLUS standard was taken back in 2007, within the framework of energy-saving standards Energy Star of the fourth revision. This standard requires the manufacturers of power supplies to provide 80% of the efficiency of its devices at various loads, - 20%, 50% and 100% of the rated power.

It follows from this that to ensure the maximum efficiency of your power supply, it must be loaded at least 20% of its rated power. It is absolutely not correct when the user acquires the power blocks "with a reserve" by 900 and 1200 watts. When the power supply is selected, refer to the fact that without load on the system, the load on it should not fall below 20% and it must have a certificate of compliance with 80 Plus.

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Justice for sake, it should be noted that today the standard 80 Plus. Differentiated to the following categories:
- 80 Plus.
- 80 Plus Bronze
- 80 Plus Silver
- 80 Plus Gold
- 80 Plus Platinum.

The difference between standards is to ensure higher efficiency in the 80 Plus family of the standard. If with a 50% load of the 80 PUS power supply unit provides an efficiency at 80% efficiency, then expensive power supplies appropriate 80 Plus Platinum standards provide an efficiency at 94% and higher.

Energy saving: motherboard.

To date, motherboards develop as quickly as possible, not behind the development of processors. It should be understood that motherboards consist of various sets of controllers, ensuring the coordinated work of which, and is the main task of the motherboard. In most cases, the energy consumption of the motherboard depends on the type of the applied northern and southern bridge. Modern northern bridges have significantly reduced their power consumption, which resulted in a decrease in the size of their cooling systems. Many users remember the times when the cooling system of the northern bridge consisted of several thermal tubes connected to cooling radiators. The emergence of the latest generation of system logic from Intel made it possible to move back to the level of ordinary radiators.

Due to general trends, many famous manufacturers of motherboards, such as Gigabyte, ASUS, MSI Demonstrate their new "eco-friendly" exhibitions. As a rule, environmentally friendly solutions is achieved by optimizing the processor and video cards, are the main consumers of any system unit. As a rule, this is carried out due to the use of multiphase stabilizers of processors voltage.

Modern motherboardsapplied in power saving from six to twelve voltage stabilizers. These schemes significantly increase the stability of the supplied voltage, but increase power consumption. Therefore, manufacturers of "eco-friendly" motherboards are equipped with their technologies, which, with a low load on the power system, turn off part of the phases, and the power of the processor is carried out due to the same-two phases of voltage stabilizers.

When buying a motherboard, you should also be more attentive. Acquisition "Fucking" motherboard Always turns into increased power consumption. If you never need a FireWire port, you should not overpay for it, and then pay monthly for the electricity that consumes its controller on the motherboard.

Energy saving: processor.

Leading manufacturers of processors AMD. and Intel Over the past decades, they are reducing the power consumption of their products. It should be paid properly, the entire relay was started by AMD, in which she kept lasting leadership for two to three years. There were times when AMD processors with COOL "N" QUIET technology had significantly less power consumption, rather than processors from Intel Linek Pentium 4 and Pentium D.

Intel quickly caught his backlog and introduced technology EIST. - Enhanced Intel Speedstep Technology, which has shown perfectly in recent generations of processors. While the new processors from the company Intel will enjoy all new and new energy saving technologies and increase productivity, we do not see any essential jerks from AMD.

As you know, the key energy consumer of any personal computer or laptop is precisely the processor, so we will focus on issues of reducing its power consumption.

In order to understand how to reduce power consumption, you must presented clearly for yourself, from which it depends. Energy consumption of the modern processor depends:
- from the supply voltage supplied to transistors,
- frequency of the processor. The frequency of the processor is formed from the product of its multiplier to the tire frequency.

In essence, technology COOL "N" Quiet and EIST. Discover power consumption precisely at the expense of these two parameters. Unfortunately, most often we face work with a voltage of the processor, but with its work frequency. When the load is reduced to the processor, energy-saving technologies reduce the processor multiplier and thereby achieve a reduction in the power consumption of the processor. When the processor load appears, the multiplier returns to the previous values, and the processor works, as nothing has happened. Unfortunately, this method of reducing power consumption does not always allow to achieve high energy efficiency. Let's show on the example.
The Core 2 DUO processor is selected as an example with a nominal frequency of 2.0 GHz.

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From the presented diagram, it can be seen that the temperature of the processor without inclusion of the power saving mode, at the nominal multiplier X12 and the supply voltage of 1.25 volts, we have the operating temperature of about 55-56 degrees in a simple.

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After serving the load on the processor, under similar conditions of work, we fix the average temperature of the work of about 71-72 degrees, which was recorded on our diagrams.
The temperature of the nuclei is removed from the internal sensors, so the errors are minimal. Considering the fact that there is a direct relationship between the power consumption of the processor and its working temperature, we will focus on this parameter when evaluating its energy efficiency.
The next stage we reduced the multiplier to the minimum possible values, to 6. The frequency of the processor was 997 MHz, roughly can be rounded up to 1 GHz. The supply voltage remains unchanged, in the area of \u200b\u200b1.25 volts.

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From the submitted data, it is clear that in idle mode, the working temperature of the processor has changed very little, it remained, as before, within 55-56 degrees. It suggests that we win very little from the simple reducing the frequency of work of the processor.

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After that, we have subscribed a load on, but the multiplier and the working voltage of the processor was left at the same level. Naturally, such testing matters only from the practical side, we do not recommend it in life. This is due to the fact that it is from the frequency of the processor its productivity depends, and no one buys a high-frequency processor for its subsequent work at low frequencies. After stabilizing the temperature values, we obtained an average operating temperature equal to 65-66 degrees, which is six degrees lower than when the processor is operating at a nominal frequency of 2 GHz.
From this all follows that it is really energy saving from a decrease in the processor's working frequency by changing the value of the multiplier takes place, but it is not the level that we would like to see in each case. Therefore, we proceed to work with the voltage of the processor.

Our processor and motherboard allow you to change the processor power supply voltage in the range of 0.95-1.25 volts. The step is 0.0125 volts. This is due to the fact that the processor is installed in a laptop, whose motherboards rarely make it possible to change the operating voltages of components in wide ranges.
In order to prove the effectiveness of reducing the processor's working voltage in terms of reducing its power consumption and heat dissipation, we will leave its operating frequency at 1 GHz, but in parallel to reduce the working voltage to the lowest possible values \u200b\u200b- 0.95 volts.

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This manipulation allowed us to reduce the processor downtime to 45-46 degrees, which is presented in the diagram. In this mode, we achieve the most possibly low power consumption of the processor. Reducing the operating voltage up to 0.95 volts allowed us to reduce the operating time of idle for 10 degrees !!!

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To assess the effectiveness of the method of reducing the working voltage of the processor, we have subscribed to it. As a result, we obtained the operating temperature in the load equal to 50-51 degrees, while without changing the voltage and similar performance of the system at a frequency of 1 GHz earlier we received 65-66 degrees. The data we received are fixed in diagrams.

Processor power consumption: conclusions

- Of the foregoing, it follows that to ensure high energy efficiency processor Do not only reduce the working frequency of the processor, as made by many laptops and personal computers within the framework of energy-saving technologies from Intel and AMD. Reducing the frequency of the processor should always be accompanied by a decrease in its operating voltage.

Given the fact that any processor can work when low voltage with more low frequenciesah of your work, you should choose your minimum stable voltage for each frequency of its operation.

To determine approximate workers voltages For each frequency (multiplier) of the processor, it is sufficient to build a schedule of direct dependence of the minimum voltage from the frequency by applying maximum and minimum values. This will greatly facilitate the work of novice users.

- To ensure the necessary energy efficiency of the processor, it is necessary to properly configure existing technologies or apply third-party software products that could reduce the frequency of the processor, its voltage at low load and increase them when it increases.

Energy saving processor: Rightmark CPU Clock Utility (RMClock)

The utility has a small weight, order 250 kilobyte. No installation required, just unpack it in the selected folder and run the RMClock.exe file. For simplicity, reference to the archive with the program will be presented at the end of our article.

At the time of writing the article Last program version 2.35. It has the following functionality as part of free use:
- control of the clock frequency processors,
- trottling control,
- control of the processor load level, processor cores,
- control of the working voltage of the processor,
- monitoring the temperature of the processor / processor cores,
- constant monitoring of the specified parameters,
- the ability to change the voltage of the processor from the operating system,
- the ability to change the processor multiplier (its frequency) from the operating system,
- automatic frequency control and voltage processor Depending on the supplied load on it. The concept is called "Perfomance On Demand" or "Performance on demand".

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Running the software product, you fall into one of the partitions of its menu. We list all the functional Rightmark CPU Clock Utility in order. In the About section, information about developers, their website, and reference to the license agreement are presented. The basic version of the product is supplied free for non-commercial purposes, no registration is required. There is a professional version that provides a much wider functionality of the system settings and is a symbolic 15 dollars. For novice user opportunities base version Quite enough.

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Bookmark " Settings"The program settings are presented for the convenience of use. Unfortunately, Russian language packagewho met in previously released versions of the product, in our case did not turn out, but there is nothing terrible. This tab has the ability to select the color of the design and, please pay attention - the autorun mode.

For the autorun mode corresponds to subsection " Startup Options.". Rightmark CPU CLOCK UTILITY autorun when loading the operating system allows you to easily solve energy saving issues without interference in BIOS ComputerIt is especially useful when BIOS does not provide any possibilities for changing the operating voltage and processor factor. This is found in the BIOS "Ah of modern laptops.

Putting a tick in the point window " Start Minimized To System Tray"You will relieve yourself to constantly close the program window at the next launch. It will perform your tasks after automatic start with pre-coagulation.

Item " RUN AT Windows Startup: "Allows you to install the automatic program product launch and choose how to do it. In our case, we automatically run through the registry, it is also possible to automatically start through the" Auto-loading "folder. Both options work perfectly, ranging from Windows XP finishing Windows 7.

It is possible to record the necessary parameters of the processor in Log file.. This parameter is necessary to determine the causes of the unstable operation of the system.

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Bookmark " CPU info"Presented information on the processor, its characteristics currently. Listed supported energy saving technologies. The more modern processor, the more technology it supports.

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Bookmark " Monitoring"The chart changes in the operating frequency of the processor kernel, its trottling, load on it, the multiplier, operating voltage and temperature. The number of tabs corresponds to the number of processor cores.

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In the tab " Management"The user is given the ability to select the multiplier switching method, the methods for determining the actual load on the processor, the integration of the software product with energy-saving technologies of the operating system.

Item " P-STATES TRANSITIONS METHOD"Allows you to select the transition method from one specified voltage multiplier combination to another. The following selection features are available:
- Single-Step: The multiplier switches in a step of equal to one. That is, when moving from a multiplier 10 for a multiplier 12 will always be an intermediate link 11.
- MULTI-STEP: The transition will be carried out with a variable step. In the case of our example, from 10 at once to 12.

Item " Multi-CPU Load Calculation"Allows you to determine the method for determining the processor boot. This parameter will affect the switching speed combination multiplier on the processor. In each case, it is selected based on the individual features of the user's work. Usually, we do not change this parameter and leaves on the value indicated on the screen, which means that means that the assessment will be carried out at the maximum load of any of the processor cores.

Item " STANDBY / HIBERNATE ACTION"Allows you to select the program action when you go to hibernation or sleep mode. As a rule, leaving the current profile of the work is quite sufficient.

In chapter " CPU DEFAULT SETTINGS"The following items are presented:
- Restore CPU Defaults on Management Turns Off, which allows you to return the initial parameters of the processor after selecting the "No Power Managemet" mode.
- Restore CPU Defaults ON Application EXIT, which allows you to return the initial parameters of the processor after turning off Rightmark CPU Clock Utility.

In the "CPU Defeaults Selection" section, the method for determining the combinations of the voltage multiplier from the processor is selected:
- CPU-DEFINED DEFAULT P-STATE, the combination is determined by the processor,
- P-STATE FOUND AT STARTUP, combinations are determined when loading the program,
- Custom P-State, combinations are installed manually.

Item " Enable OS Power Management Integration"Allows you to create a profile in the power consumption schemes called" RMClock Power Management ".

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In chapter " Profiles"The user is proposed to specify the most combinations of the voltage multiplier, the P-state. First, it is proposed to select profiles depending on the power consumption mode, is a network or battery / UPS.

Below are invited to choose processor multipliers and voltage for them in each case. As a rule, I choose three meanings:
- minimum multiplier and minimum voltage for it,
- Maximum multiplier and the minimum working voltage for it,
- The average multiplier value, and the voltage for it is set to the program itself based on the maximum and minimum values.

As a rule, a similar approach is suitable for most laptops and personal computers. Naturally, there are exceptions, and the user has to close the minimum voltage for each multiplier.

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Then install the checkboxes for selected profiles In the appropriate varieties of the program:
- No Management - without control, does not need the settings
- Tabs "Power Saving", "Maximal Performance", "Perfomance On Demand" are essentially equivalent and allow you to set the ranges of multipliers change processor.

For example, in our case for the tab " Power Saving."We have chosen the minimum possible multiplier and voltage, for the Maximal Performance tab, the maximum multiplier and the minimum operating voltage at a given frequency at the processor.

In the Performance section on the request " Perfomance on Demand."Three combinations of voltage multiplier were chosen:
- X4-0,95 VOLT
- X9-1.1 Volt
- X12-1.25 Volt.

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Then look at the icon in the desktop notification program Rightmark CPU CLOCK UTILITY And select the necessary processor parameters, which should always be shown and select the current profile of the work. I always put a processor frequency for monitoring and its work temperature, which is always convenient and partly interesting.

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Figure presents three pictograms In the area of \u200b\u200bdesktop notifications:
- Rightmark CPU CLOCK UTILITY program pictograms,
- current processor frequency,
- Its current temperature.

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The screenshots present the processor operation charts in " Performance on demand". It can be seen as a software product with an increase in the load on the processor stepwise increases its multiplier and the voltage at first to x9-1.1 volts and, if necessary, to the maximum x12-1.25 volts. As soon as the load drops, everything is dropped, everything is returned back.
Such adjustment practically does not affect the final performance of the system.

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In the tab " Battery info."It is proposed to choose the methods of a notification of the rechargeable battery of the laptop.

In the tab " Advanced CPU Settings"It is proposed to choose the respondent processor temperature sensors, including energy saving technologies.
All these energy-saving technologies are described on the site. Intel. We just want to say that, as a rule, their inclusion does not affect the stability of the system, so - why not include them?

Our processor refers to the early family of processors. Core 2 duo.. Modern processors support non-active technologies:
- ENGAGE INTEL DYNAMIC ACCELECE (IDA)
- Enable Dynamic FSB Frequency Switching (DFFS)

First technology Allows the processor to increase the factor of one of the nuclei in the absence of a load on the second. For example, two cores of the processor are operating at a frequency of 2.2 GHz. The processor estimates that the load is supplied only to one nucleus, then its multiplier will be increased, and it will start working at a frequency of 2.4 GHz. Technology is interesting, but dangerous on overclocked processors.

Second technology allows you to achieve even more strong decline The processor operating frequency in idle modes. Earlier, we talked about the final frequency of the processor - it is always a product of the multiplier on the frequency of the system tire. Modern Intel processors within DFFS technology make it possible to reduce not only the multiplier value, but also the frequency of the tire, which allows to achieve even lower frequencies. This technology is also dangerous for overclocked processors, as you can get instability from RAM.

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Perhaps this is all that we wanted to tell about the software product. Rightmark CPU CLOCK UTILITY. It remains to advise watching its updates. At the same time, it does not make sense to be updated when you have already been working steadily for many months. It makes sense to look new version When changing the processor or transition to a more modern operating system.
Using the program Rightmark CPU CLOCK UTILITY It will allow you to extend the life of not only your processor, but also the motherboard nutrition system, and also significantly reduce the noise from the processor cooling system, which will not be lit for its cooling when you print, watch movies or just flipping the page on the Internet.

Power consumption of the processor: Determine the minimum operating voltage

In his article, I repeatedly pointed out that it is important to determine the minimum work voltage For each frequency of the processor. This is done by samples and errors. As a rule, the following cycle of tasks is sequentially performed:
- reduction of voltage per item,
- checking the stability of the processor in the stress test program product,
- decrease or raising voltage per item depending on the results of stress testing.

For stress testing processors, there are many software products. They were described in one of our articles. I believe that the most valuable of them is Prime95. The link to it will be provided at the end of the article. It is completely free and accessible to download online.

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The latter version was released in 2008, just when it was necessary to implement multi-test in testing. It is possible to select various testing methods, indicate the duration of testing, frequency of testing, etc.

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Select the test method in the section " Options."=> "Torture Test"And launch it. The duration of testing is completely dependent on you. As a rule, when determining the approximate minimum voltage, I wait or first error, or spending testing for half an hour. If half an hour, the test passed without errors, reduce the voltage to one point and forward again.
After you have decided on minimal voltage Finally, it makes sense to leave the test for the night. For several hours of painstaking work, it is almost always possible to identify emerging errors.
Often, the operating system freezes or at best, issues " blue screen of death". This suggests that the voltage is underestimated and an error occurred," the operating voltage on the processor for this frequency should be raised.

Picture Clickable -

In our case, we have determined the minimum working voltage for of our processor. As it turned out, at the maximum frequency of 2 GHz, our processor 1.25 volts are not needed at all. It works quite consistently at 1.00 volts. The stability of the operating system was discovered at 0.975 volts mode, but Prime95 reported an error that disappeared after raising the voltage to 1.00 volts.

As a result, we have

:
- processor with an unchanged level of performance and frequency of 2 GHz,
- the maximum operating temperature in the load of 62-63 degrees, instead of the usual 72 degrees,
- lower power consumption that allows without any power consumption schemes from Acer, Asus, Samsung, Gigabyte to extend the duration of the laptop operation from the battery without losing the level of performance,
- Lower power consumption will reduce electricity costs, especially if you specify the data of the values \u200b\u200bin the programmatic product described above Rightmark CPU Clock Utility.

In fact, such a low operating voltage of the processor for an overclocker is always talking about one thing - about its high acceleration potential. But other articles will be devoted to the nuances of overclocking, the topic of overclocking the processor goes beyond the scope of the topic of energy saving. Conclusion.
After reading the article, the user should have a question: "Does manufacturers really make so inept that they themselves do not lower the working voltage of processors, especially in laptops, where is it so critical?" The answer is simple and is that processors are produced massively, laptops also come from the conveyor. Not in the interests of manufacturers to delay the production process, so someone is lucky and its processor shows the wonders of overclocking, and someone refuses to do this, someone has a processor at a voltage of 1.175 volts, and someone has stable and at 0 , 98 volts. Buying electronics, is always a lottery. What is hidden under the label in each particular case, it is known only in practice.
In conclusion, I want to thank the developers of software products Rightmark CPU CLOCK UTILITY and Prime95With which our portal MEGOBABRAN Hands the Golden Honorary Medal. We are waiting for your questions and remind that everything you do with your electronics, you do at your own risk.

Rightmark CPU CLOCK UTILITY You can find by.
The program described in the article Prime95 You can find by.

Introduction

Enthusiasts are closely monitored by the possibilities of overclocking processors. They spend a lot of time to find answers to the following questions: how quickly can one or other processors be accepted? What does the voltage level required? What cooling solution will be better?

Acceleration allows you to increase CPU performance to the level of more expensive processor models, but the opposite direction is also possible. You can usually reduce the supply voltage of the processor to improve the efficiency of work without changing the performance.

Voltage, clock frequency and energy consumption

Clock frequency - one of the most important parametersThe performance of high clock frequencies is usually required to achieve high clock frequencies. Taking into account all the downloaded precisely, the tension plays the most important role in the final energy consumption, and the role of the clock frequency is still secondary. The increase or decrease in the clock frequency affects the power consumption almost in direct proportional dependence, and the dependence of the dependence is quadratic. It is for this reason that an increase in voltage always more significantly affects energy consumption than to increase the clock frequency.

Of course, the reduction in working voltage also significantly affects energy consumption, so we decided to more deeply investigate this issue.

Reduced voltage processors

Many mobile processors are somewhat modified versions of conventional CPUs with reduced voltage. Take, for example, intel Core 2 Mobile Processors . They are characterized by optimized power consumption, but in comparable conditions they will work with the same productivity and consume as much energy as their desktop "counterparts". The Core 2 Duo T line is declared with maximum power consumption of 35 W, the line P is limited to a thermal package of 25 W and so on.

But there are cost-effective processors and for desktop computers. AMD offers processors with optimized power consumption with suffix "E" (Phenom II X4 900E, 905E, and Phenom X4 9350E.). Intel launches processor line Core 2 quad "s" that provide performance at the level of standard models, but remain within the thermal package of 65 W instead of 95 W. Although the cost-effective versions of processors are more expensive, they were very impressed by us, ensuring a decrease in power consumption in inaction mode and under load.

Do it yourself?

Is it possible to turn the processor in the cost-effective version with your own hands? Acceleration and raising voltage became very popular, but what about the reduction of tension? We took two MSI motherboards that were at our disposal: P45D3 Neo, we used in search for optimal overclocking Core 2 Duo But this time in a pair with the Core 2 Extreme QX9650 processor, as well as the 790FX-GD70 model for AMD Phenom II X4 955 tests.

Platforms: AMD 790FX and Intel P45

To explore the decrease in the Phenom II X4 955 processor voltage, we took the MSI 790FX-GD70 motherboard. This fee is the MSI top model for Socket AM3, it uses AMD 790FX chipset that supports all the latest AMD processors; The board is equipped with ATI CROSSFIRX technology (thanks to the four slots of X16 PCI Express 2.0) and a large number of functions, useful enthusiasts. The manufacturer decided to equip the board with the function of hardware acceleration, stabilizer with 4 + 1 phases with dynamic switching, as well as a large (but not excessive) cooling system on heat pipes for chipset and voltage stabilizers. BIOS allows you to set the DDR3 memory frequency to 2133 mt / s. RAID is supported on all six SATA ports 3 Gb / s through the southern bridge SB750; There are additional SATA ports, FireWire 400 and two Ethernet slots 1 Gb / s, not to mention the sound codec HD 192 kHz.

However, this time we hardly need such a set of functions, since the purpose of the project was saving energy. The voltage stabilizer with five phases should be effective, and the enthusiast level fee itself is filled with high-quality components capable of satisfying our ambitions. However, we were still somewhat disappointed that it is impossible to reduce the voltages of the chipset and memory less than the nominal. Perhaps MSI should add such a feature in the following BIOS versions.

For CORE 2 QUAD processor on Socket 775 (we used Core 2 Extreme QX9650) We took the P45D3 NEO motherboard, which faded themselves in our optimal overclocking tests Core 2 Duo . The board is built on the P45 chipset, but this is not a product for enthusiasts: you have to be content with the three phases of the voltage stabilizer, there is no complex cooling system on heat pipes, and standard functions The chipset complements only a few options. Additional information about the board is given in the article " Intel Core 2 DUO: analysis of overclocking, performance and efficiency "But we still used this fee for our voltage reduction project, since other products (including Gigabyte X48T-DQ6 and ASUS P5Q Deluxe) also did not provide the options for reducing the voltage of other components in addition to the processor.

How to reduce the voltage?

Experienced overclockers may miss this section, and we recommend everyone else to familiarize yourself with some features associated with a decrease in processor voltage.

Drooping.

The first thing you need to know is the processor voltage that is set to BIOS (automatically or by the user) may not match the voltage Vcore on which the processor will work. In fact, the BIOS is determined by the maximum processor voltage, and the efficient voltage is usually lower. It may even change depending on the working conditions of the processor (for example, temperature), which change when switching the CPU from the idle mode into the load mode and vice versa.

This behavior is quite justified, since the conductivity of the crystal is improved as the CPU is heated under load. If the voltage is not changed, the current will increase, that is, the current and temperature will raise each other. The special Drooping mechanism slightly reduces the processor voltage under load so that the CPU remains within the electrical specifications.

If you use tools such as CPU-Z to read the efficient processor voltage, try checking the specified voltage using CoreTemp - and you will notice that the two values \u200b\u200bwill vary. The difference between the specified and efficient voltage in idle mode is called "Offset" (VOFFSET), and the voltage difference between the inactivity mode and peak load is "DROOP" (VDROOP).

Check

The processor reaches peak voltage when it moves from the load state to the inactivity state, since the voltage never passes exactly from one level to another, but "jumps over" the level and then aligns. It is in such a "jump" processor reaches peak specified voltage.

For the same reason, it is quite easy to check, there will be or no processor with reduced voltage to work stably under peak loads: it will apply VDROop and reduce the operating voltage so that it is below the specified voltage. We used PRIME95 - a wonderful utility for loading the processor. After 30 minutes of work under the peak load without "departures", we came to the conclusion that the reduced voltage system steadily under load. This usually means that the work will be stable and in inactivity mode, since then there is a slightly higher voltage. But this is not applicable to energy saving modes similar to Intel Speedstep, which even more reduce the frequency (multiplier) and voltage. We spent all the tests of reduced voltage with active technology Speedstep, but it was not necessary for AMD Cool "N" Quiet, since it uses regular voltages and frequencies in idle mode.

As usual, you can not perceive our results of overclocking or reducing the voltage as the truth in the last instance. It all depends on you: you need to either conduct an extended set of tests, or come down with the risk that the system may not be always stable. Yes, and your results can be completely different - it is possible to return to more conservative settings (that is, a little to increase the voltage) to secure yourself. In any case, the potential for energy saving will still be very significant.

CPU AMD Phenom II X4 955 remains flagship model Companies after his announcement in April 2009. Thanks to the support of the DDR3 memory and the clock frequency of 3.2 GHz AMD was able to compete with Intel Core 2 Quad in some tests, both the processor and the platform will cost cheaper. However, before the performance of Core i7 is still far away.

The Phenom II X4 models are available at frequencies between 2.5 and 3.2 GHz (see page on the AMD Web site). The 800 processor ruler is equipped with 4x 512 KBA L2 cache on the kernel and a total L3 cache by 4 MB, and the 900 L3 cache line is 50% more. All Phenom II processors are manufactured at GlobalFoundries plants in 45-nm DSL SOI process inspection, providing low power consumption and good overclocking capabilities. It will be interesting to see how much we can reduce the tension.

Automatic settings BIOS led to the work of Phenom II x4 955 from the voltage of 1.32 V according to CPU-Z. In this case, the peak power consumption of the system was 216 W at full load on the CPU. It is quite clear that the result is where to improve.

All AMD processors with the active COOL "N" QUIET technology can switch to the frequency of 800 MHz in inactivity mode, while the standard kernel voltage decreases to 0.96 V. As seen by the final table below, the Phenom II processor switches to 0.96 V Cool mode Cool "n" quiet no matter how voltage CPU is exhibited in the BIOS. Therefore, the power consumption of the system in idle mode was always the same: 99 watts. Improve in this case there is nothing if only BIOS starts allowing voltage in inactivity mode.

We tried to set several voltage levels (see the table below) and checked the load on them using the PRIME95 test for at least 30 minutes. It turned out that the regular voltage of 1.32 V can be reduced by as much as 12% to 1.1175 V. At the same time, we reduced the energy consumption of the system from 216 to 179 W, which is a fall by 17.2%. Not bad.

Total table

AMD Phenom II X4 955
Voltage in bios.					Stub.
AUTO.	0.96 V *	99 W.	1.32 V.	216 W.	Yes
1,3125	0.96 V *	99 W.	1.288 B.	205 W.	Yes
1,2875	0.96 V *	99 W.	1.264 B.	199 W.	Yes
1,2625	0.96 V *	99 W.	1.24 B.	196 W.	Yes
1,2375	0.96 V *	99 W.	1,216 B.	192 W.	Yes
1,2125	0.96 V *	99 W.	1,192 B.	186 W.	Yes
1,1875	0.96 V *	99 W.	1,168 B.	181 W.	Yes
1,175	0.96 V *	99 W.	1,152 B.	179 W.	Yes
1,1625	0.96 V *	99 W.	1,136 B.	177 W.	Not

* Cool "N" Quiet is exhibited.

Now it is time to consider Intel Core 2 Quad. We used the Core 2 Extreme QX9650 processor, since there was no ordinary model Core 2 Quad.

The Core 2 Quad line provides solid performance at acceptable power consumption levels. The Q8000 and Q9000 line are built on the 45th Yorkfield design. Q8000 uses 4 MB of cache L2, and Q9000 6 MB or even 12 MB cache L2.

All four-core core processors 2 Quad are assembled from two 45-nm duid wolfdale crystals.

When we put the voltage in the BIOS in the "Automatic" mode, you got at Core 2 Extreme QX9650 1.256 B, as a result of which the system has consumed 185 watts at full load.

The voltage in idle mode cannot be changed directly, it will always be determined depending on the CPU voltage that you specify. In the case of the default BIOS settings, we received a voltage of 1.192 V after switching on SpeedStep technology, which lowered the multiplier to 6x, and the clock frequency of the nucleus was 2.0 GHz. The resulting energy consumption value in 94 W (see table below) is still lower than the power consumption of the AMD system at a voltage of only 0.96 V and the frequency of the CPU 800 MHz, which is rather strange.

The lowest stable voltage was 1.072 V, which we achieved with a setup in Bios 1.0785 V. With a full load, this led to the general power consumption of the system of only 148 W, that is, we received a 20% reduction in power consumption at a 16.3% reduction in the kernel voltage processor. Next step There should have been a voltage of 1.0655 V, in which we have already lost stability. Fortunately, it led to the same failed results under load and in inaction mode, which made a further decrease in voltage meaningless.

The voltage in the inactivity mode, the following from the voltage of our processor 1.0785 V, was 0.1008 V, which made it possible to obtain power consumption in the inactivity mode of 87 W. The improvement is less than 11%, but it got free, the system in tests worked stable.

Intel Core 2 Extreme QX9650
Voltage in bios.	Effective tension (DF.)	Effective energy industry. (heartless)	Effective tension (nation)	Effective energy industry. (Narr.)	Stub.
AUTO.	1,192 B.	94 W.	1.25 B.	185 W.	Yes
1,1955 B.	1,128 B.	93 W.	1,184 B.	172 W.	Yes
1,1695 B.	1,104 B.	92 W.	1,16 B.	166 W.	Yes
1,1435 B.	1,008 B.	91 W.	1,136 B.	162 W.	Yes
1,175 B.	1,048 B.	90 W.	1,104 B.	158 W.	Yes
1,0915 B.	1,016 B.	88 W.	1.08 V.	151 W.	Yes
1,0785 B.	1,008 B.	87 W.	1,072 B.	148 W.	Yes
1,0655 B.	0.992 B.	87 W.	1,056 B.	148 W.	Not

System hardware
CPU AMD.	AMD Phenom II x4 955 (45 Nm, 3.2 GHz, 4x 512 KB cache L2 and 6 MB cache L3, TDP 125 W, Rev. C2)
CPU Intel	Intel Core 2 Extreme QX9650 (45 Nm, 3.0 GHz, 12 MB of Cache L2, TDP 130 W, Rev. D0)
Motherboard (Socket 775)	MSI P45D3 NEO-F (Rev. 1.0), chipset: Intel P45, ICH10R, BIOS: 4.2 (02/18/2009)
Motherboard (Socket AM3)	MSI 790FX-GD70 (Rev. 1.0), chipset: AMD 790FX, SB750, BIOS: 1.3 (04/01/2009)
DDR3 memory	2 x 2 GB DDR3-1600 (Corsair T3X6G-1600C8D 8-8-8-24)
Video card	ZOTAC GeForce GTX 260², GPU: GeForce GTX 260 (576 MHz), video memory: 896 MB DDR3 (1998 MHz), 216 streaming processors, the frequency of the shaders block 1242 MHz
HDD	Western Digital Velociraptor, 300 GB (WD3000HLFS) 10 000 rpm, SATA / 300, cache 16 MB
Blu-ray drive	LG GGW-H20L, SATA / 150
Power Supply	PC POWER & COOLING, SILENCER 750EPS12V 750 W
System software and drivers
Operating system	Windows Vista Enterprise Version 6.0 X64 Service Pack 2 (Build 6000)
AMD chipset driver	Catalyst 9.4.
Driver NVIDIA GeForce	GeForce 185.85
Intel Chipset Driver	Chipset Installation Utility Ver. 9.1.0.1012
Intel Storage Drivers.	Matrix Storage Drivers Ver. 8.8.0.1009

Tests and settings

Tests and settings
PcMark Vantage.	Version: 1.00 PcMark Benchmark.
Prime 95.	Version: 25.7. IN-PLACE LARGE FFTS

Test results

We do not have a graph showing the power consumption of AMD Phenom II X4 955 in inactivity mode, since the AMD processor voltage does not change. After activating the Cool "n" function, the Quiet load processor always operates at a frequency of 800 MHz with a voltage of 0.96 V (at least on our MSI 790FX-GD70 motherboard). Therefore, the AMD system has always consumed 99 W in idle mode.

The graph shows the power consumption of the Core 2 Extreme QX9650 system in idle mode on all tested voltage levels. At a voltage of 1.008 V, it is possible to obtain energy consumption of 87 W, and at a voltage of 1.192 in the default power consumption is 94 W.

Energy savings from stress reduction in the case of the flagship processor AMD turned out to be very significant. We started with a regular voltage of 1.32 V, which gave the peak energy consumption of the system of 216 W, after which they received only 179 W under the load at a voltage of 1.175 V. Energy savings were 37 W or 17.2% - quite significantly, since the saved energy would be enough For nutrition, for example, 20 "contemporary display!

Can the Intel system exceed 17.2% energy savings under the peak load? Maybe: in this case, the minimum stable voltage under load was 1.078 V instead of 1.255 V, and the power consumption of the entire system of 148 W instead of 185 W - 20% decrease.

PCMARK power consumption and efficiency

We made PCMark Vantage performance measurements and power consumption when default settings and optimized AMD and Intel systems.

In the case of the Phenom II x4 955 system, the average power consumption was reduced from 157 to 141 W, that is, the improvement was 10.2%. The Core 2 Extreme QX9650 system was able to reduce energy consumption from 135 to 117 W, that is, the result turned out to be impressive, given the computing power, which is superior to the AMD top processor used by us. The Intel system reduced average power consumption by 13.1%.

Consequently, the total energy (in Watt-hours), spent on the run also decreased: by 11.4% from the AMD system and by 12.4% from the Intel system. Not bad!

Finally, we correlated the results of PCMark Vantage with the average power consumption of two systems (performance points per Watt). Remember that two machines provide former performance after voltage optimization. The system on AMD Phenom II X4 955 was able to improve the energy efficiency of 11.6% in the PCMark Vantage test. The Intel system has improved the result of 13.8%.

Conclusion

We tested two High-End processor from AMD and Intel on modern MSI motherboards, which made it possible to analyze the potential energy savings, which can be obtained by reducing the processor voltage. Of course, we also intended to reduce the voltage at memory or chipsets to get additional savings, but none of the materials considered maternity cards allowed us to modify the components. We looked at the Asus P6T and Rampage II Gene, Gigabyte Ma790Fxt-UD5P and X48T-DQ6 cards, but ultimately stopped at MSI 790FX-GD70 for Socket AM3 and P45D3 Neo for Socket LGA775.

AMD Phenom II X4: energy consumption is 17% lower, efficiency is 11.6% higher

Peak energy consumption under load decreased by as much as 17% when setting the minimum stable voltage, which we found in Phenom II x4 955. Since the performance has not changed, we received an increase in efficiency (performance per WATT) 11.6% in the PCMark Vantage test. AMD Cool technology "N" Quiet somewhat slowed down our voltage reduction efforts, since in inactivity mode, it always switched to the standard mode, regardless of the voltage exhibited. And power consumption in inactivity has always been 99 W.

Intel Core 2 Extreme: power consumption 20% lower, effectiveness by 13.8% higher

The results were even more significant on our test system Core 2 Extreme QX9650, where the power consumption under the peak load decreased to the impressive 20% without any performance loss. This made it possible to improve the performance at Watt PCMark Vantage by as much as 13.8%. Since the Intel processor voltage in SpeedStep energy saving mode depends on the set of the kernel voltage, the power consumption in inactivity is also noticeably decreased - until only 1.008 V. This gave energy savings in an increase of 8%.

Should I save energy?

We were impressed with the relatively wide tension reduction tolerances, since it was assumed that the problems would begin much earlier. But AMD and Intel systems showed that modern processors Can work with significantly less voltage. We were able to submit a 16% less voltage on the AMD Phenom II X4 processor, and the Intel Core 2 Extreme processor is 16.6% less. All this made it possible to obtain savings of 17-20% under the peak load in both systems.

However, you need to make sure that your reduced voltage settings provide reliable operation, so we recommend approaching this process Caution. However, you do not need to seek a 16% stress reduction - even a 10% reduction will allow free to reduce the power consumption of the system without any damage to performance.