The volume of buffer memory. What to choose a hard drive so that it worked well and for a long time. Cache memory is one of the HDD parameters

Which to choose hDD. The hard drive also need to choose correctly so that it is shridly, quiet and reliable. Unfortunately, you do not have time to look back, as the disk is already filled under the eyebreaker. There are users who, even after several years, the disk space remains quite enough to work for another 10 years.

But this is usually the exception rather. Many places on the hard disk are disastrously lacking, and sometimes just somewhere. Now the computer is not just a printed machine. Many users do serious projects on it and earn good money. A hard disk, as you know, keeps a lot useful informationTherefore, it is not necessary to buy it.

What to choose a hard drive

It all depends on what you will do on your computer. It is best if on your computer will not be one hard drive, but two or even three. How to install such a disc, read. On the main disk you will have an operating system, and on the other it is better to store your data.

Usually there is not enough space on the hard disk. Do not think that you are one. Now I am even wondering how I once grabbed 10 GB. The most offensive thing is that all the files are needed and the roads, and you don't want to delete anything at all.

Any instrument has its own parameters and resources, and the hard disk of the computer is no exception. If you just come to the store and ask the disk, then you can advise not at all what is needed, but most likely what is more expensive. Why overpay, if you can take the same or.

Where else can you store your data besides hard disk

Previously, it was possible to record your data on the "Dawn" (CD or DVD) and sleep peacefully. Now everyone has so much information on computers that everything to rewrite on the CD is no longer any possibility. At best, you can rewrite anything important.

And still it is not very convenient. You will not wear a whole portfolio with CD or DVDs and insert one after another into a drive to find the information you need.

You can buy a small size, but large by volume external disk And wearing it with you. But, again, there is no guarantee that he ever "glucnet". And then "goodbye" valuable information. I recently had it. But now is not about it.

External hard drive 2.5 '

Hard disk capacity (volume)

Under the operating system, a large amount of disk is not needed. Since now on sale the minimum volume of the 500 GB disk, then this is enough for your eyes. But another disc, if you constantly swing something from the Internet, you need to take as much as possible.

Spindle rotation frequency

Under the operating system you need a disc with a good spindle speed. With a small speed, your operating system will slow down, whatever memory is, and whatever the microprocessor is not smart.

Everything should be in the complex. Otherwise, you throw out "Money to the Wind". You can not save on hard disk!

Modern hard drives (HDD) 2.5 and 3.5 "have a spindle speed of 5400 or 7200 rpm. The higher the speed of spindle speed, the higher the speed of the disk.

For home Computer hard speed the disk on which the operating system will be installed, graphic programs And your games should be at least 7,200 rev / minutes.

If you buy a disc for the office, it is enough and 5400 rpm. The same speed is also suitable for data storage, i.e. second tough disk, especially since it is cheaper.

There are drives with SAS or SCSI interface, with a speed of 10,000 and 15,000 revolutions per minute, but they are used for servers, and are not cheap.

SCSI Hard Drive

But if you have old computer and hard iDE disc, then the choice is not big, and about the good speed of the disk spindle you can forget. Yes, and find such a disc is already problematic.

How to define an old hard disk or not

If your disk has a wide loop, then this is an IDE interface. In new computers, they are no longer used, and the speed of these discs is small.

Cable for IDE disk

New computers are installed hard drives with SATA, SATA 2 and SATA 3 interface.

SATA disk connection cable

SATA disk data transfer rate is 50% higher than the IDE disk.

SATA, SATA 2 and SATA 3 discs are interchangeable. But the data transfer rate from SATA 3 is much better than that of SATA.

Please note that the SATA and SATA2 disk cable is not suitable for SATA3 disk. They have frequency characteristics Different, although the connectors are the same and they will still work. The cable (cable) for SATA3 is thicker and usually black.

It is also important to know which type hard SATA disk supports your motherboard, otherwise the disk will not work at full power. But this is not critical. But if the motherboard is very old, then it can not support SATA disk, i.e. It will not be connector for him.

Buffer size or memory cache

The following item for selecting the disk is the volume of cache memory (buffer memory). There is an 8, 16, 32, 64 and 128 MB cache. The higher the number, the better speed Data processing.

16 MB is suitable for storage, and it is better to buy from 32 MB under the system. If you are scheduled, then for such programs, like photoshop and autocadus, it is better to take a hard disk with cache - 64 or 128 MB, especially since the price difference between them is not significant.

Average linear reading rate

Linear read speed means the speed of continuous reading of data from the surface of the plates (HDD) and is the main characteristic reflecting the actual speed of the disk. It is measured in megabytes per second (MB / s).

Modern HDD discs The SATA interface has an average linear speed Reading from 100 to 140 MB / s.

Linear speed reading HDD. The discs depends on the density of data recording on the magnetic surface of the plates and the quality of the mechanics of the disk.

Access time

This is the speed with which the disc finds the required file after contacting it. operating system or any program. Measured in milliseconds (MS). This parameter has a big impact on the speed of the disk when working with small files and not large - when working with large.

Hard drives have access time from 12 to 18 ms. A good indicator is the access time 13-14 ms (depends on the quality of (accuracy) of the mechanics of the disk).

Now there are new hard drives - SSD consisting of some chips, but they are very expensive and therefore not intended to store data. They are good for programs only. SSD discs There are no spindle, so completely silent, do not heated, and very fast.

And the most important! Try not to install hard drives back to each other. Better if there is more space around them, because In the process of work, they are strongly heated and can fail from overheating.

And even better, especially in summer - cool them by opening the computer cover and sending a fan on them. Overheating for hard disk Also destroyed, as for the video card and microprocessor.

Any firm manufacturer disks, there are more expensive wheels and cheaper. But this does not mean that chetsuritis firms. Simply one products for state employees, and the second for more well. And those and other discs are made on conscience, but the details from different materialswho have different dates of wear.

Hard drive manufacturers

Basic manufacturers hard disks (HDD) are:

Fujitsu. - Japanese company, previously famous high quality its products currently presented small quantity Models and is not very popular.

Hitachi. - The Japanese company, as before, and is now distinguished by the stable quality of hard drives. When Hitachi's Hard Drive is not lost, having received good quality for an acceptable price.

Samsung - This Korean company. To date samsung company Produces the fastest and high-quality HDD discs. The price of them may be slightly higher than that of competitors, but it is worth it.

Seagate. - American company, pioneer in technology. Now the quality of the hard drives of this company, unfortunately, leaves much to be desired.

Toshiba. - Japanese company. Now is represented by a small amount of models in our market. In this regard, there are problems in the service of such manufacturers.

Western Digital (WD) - American company specializing in the production of hard drives. IN lately, Discs of this company are not allocated outstanding characteristics, and very noisy.

It is better to choose between Samsung or Hitachi, as the highest quality, rapid and stable.

So, the main characteristics of hard drives:

• Spindle speed
• HDD container
• Cash memory
• Average linear reading rate
• Noise level
• Manufacturer

Now you know what to choose a hard drive. Unfortunately, there are no choice in stores, so I prefer to order on the Internet. In big cities Choosing more. Therefore, do not be lazy and learn their main characteristics.

Published hard disk.

Also not bypassed the HDD interface, where the main features and differences were considered. sATA interface and outdated IDE. And of course not forgotten, perhaps the most important characteristic is hard disk volume.

In this material we will talk about the remaining characteristics of hard drives that are equally important than the above.

Hard disk form factor

On the this moment, widespread two hard factor Discs are 2.5 and 3.5 inches. Form factor, to a greater extent, the dimensions of hard drives are determined. By the way, in the hard drive 3.5 ", it is placed up to 5 plates of the drive, and 2.5" to 3 plates. But in modern realities, this is not an advantage, since the developers have determined for themselves that setting more than 2 plates in ordinary high-performance hard drives is not advisable. Although the form factor of 3.5 "does not intend to surrender at all and in terms of demand, it confidently outsources 2.5" in the desktop segment.

That is for desktop systemAs long as it makes sense to acquire only 3.5 ", as among the advantages of this form factor, you can note the lower cost per gigabyte space, with a larger volume. This is achieved due to the greater, in size of the plate, which at the same recording density accommodates a larger amount of data than 2.5 ". Traditionally, 2.5 "always positioned as a form factor for laptops, more thanks to its dimensions.

There are other form factors. For example, in many portable devices The hard disks of the form factor of 1.8 "are used, but we will not stop in detail.

Hard Disk Cache Cache

Cache memory - This is a specialized RAM, which acts as an intermediate link (buffer), for storing data, which are already read from the hard disk, but have not yet been transmitted directly to processing. The presence of the buffer was caused by a significant difference in the speed between the other components of the system and the hard disk.

As such a characteristic of the HDD cache, is the volume. At the moment, hard disks with a buffer 32 and 64 MB are most popular. In fact, buying a hard disk with a large amount of cache memory, will not give a two-time increase in performance, as it may appear on the basis of classical arithmetic. Moreover, testing has shown that the advantage of hard drives with 64 MB cache is quite rare and only when performing specific tasks. Therefore, it is possible to purchase a hard disk with more volumetric cache memory, but if it goes into significant damage to the price tag, then this is not the parameter to which you want to navigate first.

Arbitrary access time

An indicator of arbitrary hard disk access characterizes the time for which the hard drive will guarantee reading the read operation anywhere in the hard disk. That is, for what period of time, the reading head will be able to get to the most remote hard disk sector. This, to greater extent, depends on the previously considered characteristic of the rotational speed of the hard disk spindle. After all, the greater the speed of rotation, the faster the head can get to the desired path. In modern hard disks This indicator ranges from 2 to 16 ms.

The remaining HDD features

Now the following and briefly list the remaining characteristics of hard drives:

• Energy consumption - consume tight discs quite a bit. With that, often indicates the maximum power consumption, which takes place, only at intermediate stages of operation during peak boot. On average, it is 1.5-4.5 W;
• Reliability (MTBF) - the so-called time for failure;
• Data transfer rate - from the outer zone of the disk: from 60 to 114 MB / C, and from the inner - from 44.2 to 75 MB / s;
• The number of I / O operations per second (IOPS) - in modern hard drives, this indicator is about 50/100 OP. / C, with arbitrary and consistent access.

So we reviewed all the characteristics of hard drives with a small series of articles. Naturally, many parameters intersect and, to some extent, affect each other. But, on the basis of information regarding all these parameters, you can simulate a future device for yourself, and when choosing, it is clearly understood which of the models should be given the advantage in your particular case.

But such toys can turn out of old hard drives, or rather from the component of the hard disk. For example, the wheels are made from the spindle engine of the hard drive, which drives the axis with the reading head.

Effect of hard disk performance buffer

Vladimir Leonov

Modern series of hard drives of all manufacturers can be divided into two categories that differ in the size of the internal buffer (2 or 8 MB). View price list showed that the difference in the price of disks of one volume with different size Buffer in Moscow now ranges from 3 to $ 19 and depends on the manufacturer and seller. In this article we will try to show the effect of the size of the internal buffer on the hard disk performance.

we will carry out the performance of the HDS722516VLAT20 and HDS722516VLAT80 hard drives from the Deskstar 7K250 family of Hitachi. To be more accurate, since last year, the release of hard drives in Hitachi is engaged in the new HGST (Hitachi Global Storage Technologies) division (Hitachi Global Storage Technologies), formed as a result of combining its own disk production and capacities purchased from IBM. Both disks have a volume of 160 GB and completely repeat each other by the design of the mechanical part. Tested wheels had the same firmware version - V340A60A and differed only in the size of the internal buffer (2 and 8 MB, respectively).

We conducted a performance comparison of the Windows XP Professional.sp1 operating system on the computer next configuration:

Motherboard - MSI 875P Neo (MS-6758);

Processor - Intel Pentium. 4 3.06 GHz (533 FSB);

Memory - 1 GB (2-512 MB Kingston PC2700 DDR SDRAM);

Hard disk - Hitachi Deskstar IC35L090AVV207-0.

Tested discs are alternately connected as Secondary Master.

For comparison, we took tests that imitate the work of the disk subsystem in real conditions and differing in the method of productivity assessment:

ZIFF Davis Winbench 99 V. 2.0;

Futuremark PCMark2004;

Filecopy Test V. 0.5.3 (developed by the company "F-Center").

In the test ZIFF Davis Winbench 99 V. 2.0 Determines the performance of the disk subsystem when working with real applications. it good testBut, unfortunately, it is no longer supported by the developer and version of the applications used in the test, strongly outdated. In addition to performance in the test, the average access to the disk and the timeline is the dependency schedule for the data location location on the disk (Fig. 1 and 2).

As expected, the discs have the same access time (Table 1) and the charts of the read speed dependences from the location of the data on the disk for both disks coincide. In terms of performance in all subtests ahead of the HDS722516VLAT80 hard drive, and it can be said that this advantage is fully determined by the buffer work. As can be seen from the table. 1, when used file System FAT-32 The effect of buffer is usually more noticeable.

PCMark04 tests from Futuremark based on real Annexes And designed for a detailed study of computer performance. The package consists of several sections, one of which is designed to determine the performance of the disk subsystem. To test the disk subsystem, the so-called tracks are used - pre-recorded disk activity sequences recorded on some reference computer when performing various tasks. The speed indicator is the speed of processing the route, measured in megabytes per second. Four tracks are used that reproduce the hard disk operation when performing various tasks. The purpose of the tracks is clear from their name. This is loading the operating system, opening and closing multiple popular applications, copy files and imitation of the user. The results are shown in Table. 2. As in the previous test, the HDS722516VLAT80 hard drive is ahead. The most strongly of the enlarged buffer affects the copying operations and the least - on the operating system loading.

Filecopy Test V utility. 0.5.3 Developed by F-Center specialists and is intended to determine the performance of a hard disk when creating (recording) files on a disk, reading files from a disk and copy files from one disk section to another. As results, the operation time of operation and the speed measured in megabytes per second (MB / s) are shown. When creating files, prepared patterns are used - lists containing information about the length and number of files that need to be created. The pattern can be created either manually or automatically for any folder using the SCAN option, which makes it easy to create a pattern with a real distribution of files in size. We used patterns included in the Program Distribution kit. By the title of patterns it is easy to guess about their content. The test results are given in Table. 3. From the table, it can be seen that the degree of influence of the buffer size on the hard disk performance depends on the operation being performed and the average size of the file being processed. Thus, when you separately perform the operation of recording and reading files of large length (ISO pattern), the buffer size almost does not affect performance, and when copying such files, the effect of the buffer size is manifested most.

From the above results, it can be seen that an increase in the size of the buffer gives a significant increase in performance when performing most operations. Only when recording and reading the long-length files, that is, in the mode when the disk actually works in a sequential read / write mode, the buffer size has not affects performance.

Perhaps on hard drives of other manufacturers and even on tested hard drives with another version of the firmware, the effect of the buffer will affect a little differently, but it is unlikely that the difference will be significant. In our opinion, installation in computer hard The disk with an enlarged buffer is more profitable in terms of the effectiveness of investment of funds.

Cash memory or as it is called the hard disk buffer memory. If you do not know what it is, we will gladly answer this question and tell about all the features available. This is a special type of RAM, acting as a buffer for storing previously read, but not yet transmitted data for their further processing, as well as for storing information to which the system is most often drawn.

The need for a transit storage appeared due to a significant difference between the bandwidth of the PC system and the speed of reading data from the drive. Also, cache can be found on other devices, namely in video cards, processors, network cards and others.

What is the volume and what it affects

Special attention deserves the volume of buffer. Often, HDD is equipped with cache 8, 16, 32 and 64 MB. When copying large-sized files between 8 and 16 MB, a significant difference in terms of speed will be noticeable, but it is less unnoticed between 16 and 32. If you choose between 32 and 64, it will almost never be it. It is necessary to understand that the buffer often experiences heavy loads, and in this case, than it is more, the better.

In modern hard drives, 32 or 64 MB are used, less today can hardly be found somewhere. For a regular user will be enough and the first and second value. Moreover, in addition to this, the performance also affects the size of its own embedded cache system. It is he who increases the performance of a hard disk, especially with a sufficient amount of RAM.

That is, in theory, the more volume, the better performance and theme more information It may be in the buffer and do not load the Winchester, but in practice everything is a little different, and the usual user except for rare cases will not notice a special difference. Of course, it is recommended to choose and buy devices with the greatest size, which will significantly improve the work of the PC. However, this should be followed only if financial capabilities allow.

Purpose

It is designed to read and write data, however, on SCSI disks, in rare cases, permission is required to caching the recording, since the default is that the recording caching is prohibited. As we have already spoken, the volume is not a decisive factor to improve the efficiency of work. To increase the performance of the hard drive, more important is the organization of information exchange with buffer. In addition, it also fully affects the functioning of the control electronics, preventing the occurrence and other.

In buffer memory, the most frequently used data is stored, while the volume determines the capacity of this most stored information. Due to the large size of the hardware performance increases at times, since the data is loaded directly from the cache and do not require physical reading.

Physical reading is a direct circulation of the system to a hard disk and its sectors. This process measured in milliseconds and occupies enough a large number of time. At the same time, the HDD transmits data more than 100 times faster than when requesting by physical access to the Winchester. That is, it allows the device to work even if the host bus is busy.

Main advantages

Buffer memory has a number of advantages, the main of which is the fast data processing, which occupies the minimum amount of time, while the physical access to the drive sectors requires a certain time while the disc head detects the required data plot and start reading them. Moreover, the Winchesters with the highest storage, allow you to significantly unload the computer processor. Accordingly, the processor is activated as minimal.

It can also be called a full-fledged accelerator, since the buffering function makes the hard drive work much more efficiently and faster. But today, in the conditions of the rapid development of technology, it loses its former value. This is due to the fact that most modern models have 32 and 64 MB, which is enough for the normal functioning of the drive. As mentioned above, it is possible to overpay the difference only when the difference in cost corresponds to the difference in efficiency.

Finally, I would like to say that buffer memory, whatever it is, improves the work of a program or device only if there is a multiple appeal to the same data, the size of which is not more than the size of the cache. If your computer work is connected with programs that are actively interacting with small files, then you need HDD with the highest storage.

How to find out the current cache volume

All you need, it download and install free program HDTune.. After starting, go to the "Information" section and at the bottom of the window you will see all the necessary parameters.

If you buy a new device, then all the necessary characteristics can be found on the box or in the applied instructions. Another option is to look at the Internet.

RAM ensures normal operation personal computer, as well as quick execution of programs and tasks. It depends on its volume, how many tasks will be able to perform the user on its computer. There are some elements in the computer that are also equipped with memory. Consider what buffer (or cache) memory is, what are its tasks, advantages and how to calculate the required volume.

Cash memory is a temporary storage area. Here is stored information that was read from the hard disk, but not yet transmitted for subsequent processing. The need for such a repository arose as a result of the detection of a large difference between the time of time the data is read and throughput Systems.

Other PC elements have a kind buffer. For example, a printer that can proceed to perform the following task, but at the same time printing the material that was set earlier. Also with buffer memory possess video cards, network cards etc.

The main technical properties of the cache is its container and speed. Modern devices For such temporary characteristics, as well as the volume of buffers differ significantly from each other. The greater the amount of cache memory, the more information is placed in it. So, the computer can give out results without referring to the Winchester often.

Thus, the performance of the system increases itself, and the hard disk operation is indirectly extended. The latter depends directly from the user and how and for which it uses the hard drive. For example, Winchester will last longer if you watch movies in the browser, and not swing through torrent and open using a video player.

Cache volumes

When choosing a personal computer, it is important to pay attention to such an indicator as the volume of buffer memory. Since it periodically needs to be rebooted and cleansing, the larger the size of the cache - the better. Modern Pa are equipped with 8, 16, 32 and 64 MB, but buffers have a volume of 128 and 256 MB.

Although modern laptops And computers most often equipped with a large cache size, smaller - already rare. When the device is selected, users rarely pay attention to this indicator, since it does not directly depend on the price. And the parameter is not key when choosing a computer. Here you need to pay attention to other indicators, since usually the system's own memory is quite enough to perform operations.

Types of cache

Buffer memory, which is located in one fixed place, is called a direct display cache. If it is in any place, then called completely associative memory. In this case, the volume of the buffer is fully used, you can delete the data after full fill, but the search for information is sufficiently difficult.

A compromise option can serve as a Multiple or partially associative cache. In this case, the buffer strings are combined into groups. In this case, a block that corresponds to a specific group can be placed in any row, and the corresponding value is placed in the tag. Here is a kind of principle of associativity, but a certain block falls only in one or another group. It is somewhat similar to the direct display buffer.

The multiple associative type of buffer memory on the disk is most common, as it has high speed and good recycling memory. But at the same time, the direct mapping cache, which is characterized cheap and simplicity, is inferior only slightly in its characteristics.

the main task

Buffer memory is designed for temporary storage and reading information. But this indicator is not basic in determining the efficiency of the hard drive. An important data exchange algorithm with buffer is also important, as well as how well work is carried out to prevent errors.

The buffer storage contains information that is used most often. This productivity increases several times, since it is loaded directly from the cache. There is no direct access to the hard disk and its sectors, since there is no need for physical reading. This process is sufficiently long, although it is measured in milliseconds, but the data from the buffer can be obtained at times faster.

Benefits

Despite the fact that the main advantage of buffer memory is fast data processing, there are also other advantages. A hard disk with a bulk buffer can unload the processor or minimally to use it. Thus, the computer will not be overloaded and served longer.

Also cache is a kind of accelerator, providing an effective and fast work of the entire system. It shortens the start time softwareWhen the data already contained in the cache is required.

The usual user for work is quite 32 or 64 MB. A larger size loses its importance, since when interacting with the files large in volume, this difference is insignificant. In addition, overpay for a more voluminous buffer is unlikely to want someone.

How to find out the scope of buffer memory on your hard disk?

Not every user is interested in such a characteristic as the amount of cache (in contrast to the size of the hard disk). Typically, the information is contained on the package to the device. You can also find data on the network or use the HD TUNE program, which is free.

It is designed to reliably delete data, assessing what state is the device, as well as for scanning and correcting errors in the system. Additionally, you can get information about the hard disk.

To find out the volume of buffer memory in MB, you need to download the HD TUNE utility and run it. Next, in the "Information" tab, you need to find a string called "Buffer", which will show which software in this device in this device.

Experts note that a 128 MB size is suitable for a regular PC user. If the computer is used mainly for games, it is worth navigating a more cache size.