Why do you need a hard drive in a laptop. External hard drive: what kind of device it is, what it is for and how to choose the right one. Main characteristics of HDD

HDD - a component of any computer that contains data. Each computer must have at least one installed HDD for storing the operating system, programs and other user information. This disk, as a rule, is internal, or built into the computer, but since computer systems have evolved and there are different needs, threats from the Internet have appeared and different circumstances have arisen, therefore external HDs become more and more popular. external HDs are used in addition to the existing internal hard disk for storing data; they also allow the user to establish confidentiality or otherwise sensitive information on them, then disable them and store them in a safe place.

physical characteristics

Usually, external hard drive outside the computer case, in its own case. This portable case is slightly larger than itself external hard drive and it sometimes contains a cooling fan. External hard drive connected to a computer via a special interface cable that allows data exchange with external hard drive with a computer so that data can be transferred back and forth.

Why is it needed

Internet access regularly exposes computers to potential security threats such as Trojan horses, viruses, and spyware. It has become increasingly difficult to defend against these threats, even when using firewalls and antivirus software. Typically, multiple family members use the computer and the same system is introduced confidential documents with a high risk of accidental damage or loss.In addition, the space required for multimedia files has skyrocketed, digital media files often take up a large amount of space on hard disk user. All these problems can be solved with external hard drive .

Benefits

Portable or external hard drive allows the user to be able to back up or store important information separately from the main internal hard disk that could become compromised, or damaged. Confidential documents, large music files, movies, images and other files can be safely and securely transferred to external hard drive ... Another advantage external hard drive is that it is portable and plug-and-play so that other compatible computers can recognize the drive as a storage device and can use it to access files. User can easily transfer files from computer to portable hard drive or external hard drive from a computer, or all programs can be run directly from external hard drive .

Disks are different: hard, local, CD, DVD, etc. It is difficult to figure out the purpose of each of them on your own, but it is necessary. Because the age of technology requires it. So what is a disk for?

HDD

The hard drive is located in the computer system unit. What is a hard drive in a computer for? All information, operating system and all programs are stored on the hard disk. On the computer, we see the information that is stored on the hard drive in the item "My Computer": "Local drive C", "Local drive D".

Local drives

The hard drive is divided into sections: "Local drive C" and "Local drive D". Disks can store programs, files, movies, music, etc. But if you have a C drive, why do you need a D drive? The fact is that if the operating system is damaged by a malicious program, all files are damaged. To get your computer back to normal, you have to reinstall the operating system. Everything that was stored on the local C drive cannot be restored. Therefore, you need disk D, the information on it can be saved in case of reinstalling the OS. It is recommended that you keep your most important files and archives on drive D to avoid the risk of losing these documents.

CD, DVD, blu ray and more

All of the above are quite tangible things, unlike local disks. Such discs are made in the form of a plastic disc with a hole in the center. To determine what the above disks are for, you need to deal with them separately.

CD - compact discs. There are two types of CD-R, recording information on which it is possible only once, and CD-RW, recording information on which it is possible several times. Memory capacity up to 900 MB (90 minutes of recording).

DVDs are digital multipurpose discs. There are three types: DVD-R, DVD-RW, DVD-RAM. The purpose of these disks is very simple. They are needed to store information: audio, high quality video, various files and documents. DVD-R cannot be rewritten at all. DVD-RW can be rewritten up to 1000 times. DVD-RAM can be rewritten at all up to 100 thousand. time. The capacity of DVD discs is 17 GB. DVDs are more reliable than CDs.

Blu Ray (BD) is a relatively new standard optical disc. Such disks are needed to store a large amount of information (the most common volume is up to 50 GB), including for storing high quality audio and video. Rarely, there are BD disks with a capacity of up to 320 GB. They are also divided into several types: BD-R, which can be recorded once, BD-RE can record information multiple times, BD-RE DL can record information up to 50 GB multiple times.

Cleaning disc

The cleaning disc is used to clean the lenses of various turntables and disc drives. And this, in turn, is necessary so that the disks do not "slow down", and viewing information from them does not turn into a very difficult process. The cleaning disc is sold with a cleaning fluid and has a brush on the disc itself.

What is a driver disc for?

Such discs contain software, by installing it on a computer, you can access the hardware of the device for which this driver is intended (webcam, scanner, camera).

Every computer has a hard drive or, as it is often called, a hard drive, which is the main place for storing all the information used by the computer and its user. The hard disk contains the installed operating system, all programs used by the user, and data. The processor takes the information necessary for processing from the hard drive and then writes it back to the medium. The amount of information that is stored on a hard drive depends on its size.

The very first models of hard drives allowed storing up to 10 MB of data on their disks, which was a lot in those days. Nowadays, modern media can store thousands and tens of thousands of megabytes. The amount of memory on modern models is calculated in gigabytes and terabytes. This makes it possible to store a huge amount of movies, music, videos, games and other data. The significant growth in the amount of memory on the HDD is associated with the progressive development of computer technology, as a result of which movies, games and other data take up more and more free space.

Features of the design of hard drives

A modern hard drive consists of several metal disks on which information is recorded. The discs are covered with iron oxide or other special compound capable of storing the effect of a magnetic field. The number of discs depends on the volume of the media and usually ranges from 1 to 3. Metal discs are perfectly flat, smooth and balanced, so they can rotate at high speed, according to the standard it can be 5400, 7200 or 10000 rpm.

Special heads move along the discs with the highest positioning accuracy. Each disk has 2 magnetic heads. Reading data from the surface of the disks is carried out using the installation of special magnetoresistive heads, they work depending on how the magnetic field changes on the surface of the disk. The data is transmitted to the computer as a result of receiving an analog signal that is converted into digital form.

On discs, information is in tracks located around a circle. To work with the data on the media, the magnetic heads move along the tracks. The movement of the heads is carried out using a special solenoid drive. These heads can access any place on the disc due to their high rotation speed. The heads are located on both sides of the discs, so each of them does the work on one side and is fully responsible for it.

The sector on the hard drive can store 512 bytes of information, and each track of the hard disk consists of many sectors. The maximum amount of information stored on a hard drive depends on the number of sectors, heads and cylinders. By the number of disks, HDDs may be the same, but their memory sizes will be completely different. This is due to the fact that in order to increase the volume, it is more convenient to increase the density of sectors on each of the disks than to increase their number, which will lead to a significant increase in the size of the media. The development of computer technology leads to the fact that each PC component becomes smaller in external dimensions, and the possibilities, on the contrary, increase.

There are concepts such as physical disk placement and logical. The physical is how the storage medium is arranged inside, and the logical is how the computer sees it. In reality, the physical and the logical are completely different. If, for example, 3 disks can be physically installed inside the hard drive, then logically there can be any number and of any size, one logical disk can have the size of two or more physical disks and vice versa.

In the production of hard drives, it is almost impossible to avoid damage to sectors or tracks, but they are not used and are not taken into account by the media due to the markings.

Hard drives are designed for use in home PCs, and there are also for use in servers. The latter are much more demanding, because they work with a significant load and must provide high productivity and speed of work.

Characteristics of hard drives

In order to choose the right hard drive suitable for certain purposes, it is necessary to understand a large number of characteristics. The first thing to look out for is the form factor. On stationary PCs, 3.5-inch hard drives are installed, and on laptops, 2.5-inch hard drives. There are other less common form factors as well. The second important parameter is the interface through which the device is connected to the computer. Various variations of the SATA interface are used on the PC.

One of the important parameters is the capacity, on which the amount of data stored on the device depends. The speed of rotation of the shaft on which the disks are located affects the speed of working with information.

When choosing a hard disk, you should pay attention to the buffer size, which directly affects the speed of the device with information.

Each hard drive makes noise during operation, like any other mechanical device. During operation, noise can cause significant inconvenience, so you need to pay attention to its level when choosing a model suitable for your PC.

If the device is planned to be frequently transferred from one computer to another, then such a parameter as shock resistance is important. The higher it is, the less likely it is to lose information on impact or damage the hard drive.

While working with information, the disk gives the requested information at a certain speed. This indicator is called "Random access time" and the less it is, the faster the request will be transmitted.

Having an idea of all the parameters, characteristics and structure of modern hard drives, you can quickly find the right hard drive for performing the tasks on your PC.

A hard disk is a storage device that uses magnetic recording for this purpose.

Thanks to magnetic recording, it becomes possible to rewrite information on a medium many times. Winchester is the main storage of data in the vast majority of computers. Unlike a "floppy" disk (floppy disk), data in a hard drive is written to hard (aluminum or glass) platters.

There are several versions about the origin of the name Winchester. The most famous of them says that in 1973 the 3340 hard disk from IBM was released, which, during development, had the code name 30-30 (there were two plates in the design, each of thirty megabytes). This name coincided with the marking of the rifle cartridge "Winchester 30-30" (diameter 0.3 inches, powder charge - 30 grains, approximately 2 grams). There is also a version that this name appeared only because of the name of the cartridge, which was the first ammunition created in the United States for civilian smokeless weapons, which was better than the old cartridges in all respects and very quickly became widely known.

In the USA and Europe, the name "Winchester" has not been used for a long time, but in the CIS countries it has taken root and received a semi-official status, and in computer slang it has decreased to the word "screw".

How the hard drive works

A hard drive consists of several disk platters threaded onto a rotating shaft called a spindle.

The plates are coated with a ferromagnetic alloy, which, when the temperature drops to a certain value, acquires magnetic properties.

Information is read by so-called readheads. They should not touch the surface of the disks, which increases the lifespan of the hard drive. If there is no rotation, then the heads are retracted beyond the border of the disc, in order to avoid contact with its surface. Each hard disk has a so-called parking zone. This is where the heads stop when the hard drive is turned off or in low power mode.

The discs with heads are located in a sealed area with dust-free air. In addition, the device also contains a control board and a spindle drive.

When the hard drive is running, the drive first turns on, which starts the spindle. When the plates reach a certain speed, a dense air stream forms around them. Then the read heads are lowered, which read data at a distance of several microns from the surface of the disk, which is achieved thanks to the air flow. If rotation is stopped, the heads are raised again and retracted to the side.

In addition to the drive and the sealed unit, the hard disk contains an electronics unit. It includes an interface unit, buffer memory, control system, ROM and decoding unit.

All data coming to the hard drive goes to the interface unit. It connects the drive to the computer.

Since the speed of the interface part and the drive differ, a special buffer is used to equalize their speeds, which consists of high-speed memory modules.

All components of the hard disk are regulated by the control system. It receives, processes and sends signals to sensors, monitors the position of the readheads and performs many other operations necessary for accurate and trouble-free operation.

All service data of the hard drive, as well as all kinds of programs for the control system and for the signal processing system are in ROM.

The signal read from the disk is supplied in analog form. A decoding unit is used for digital conversion. It also removes noise in the original signal, which improves processing quality.

Logical representation of a hard drive

Any data written to or read from the hard disk has an address on the hard disk to find it.

To create an address space, a format operation is required, which also implies the immediate deletion of all the contents of the hard drive.

Every hard drive has circular areas on the surface of the drive called tracks. The tracks themselves are divided into sectors. Each sector of each track is the same size.

In the case when the hard drive consists of several plates, the concept of a cylinder is introduced. A cylinder is a set of tracks on the surface of the plates that are at the same distance from the center.

In a hard disk with one platter, addressing occurs by track and sector numbers. The required area is formed by their intersection. If there are many platters in the hard drive, then the address is set by the cylinder number, which determines the tracks, the number of the read head, which determines the required plate and the sector number.

Basic parameters of hard drives

The main parameters of today's hard drives are their size, capacity, connector, rotation speed, power consumption, buffer size, random access time, information transfer rate, noise level, and shock resistance.

Among these characteristics, the main one is storage volume... This value determines the amount of information that can be stored on it. Now popular are 500 gigabyte and one terabyte drives for desktops, as well as 320 and 500 gigabyte hard drives for laptops.

Information transfer rate and spindle speed are also very important parameters. These characteristics have an impact on the speed of data transfer between the system and the drive. Spindle speed displays the number of revolutions of the disk per second. The higher the speed, the faster the surface data will be read. Baud rate displays the speed of data exchange between the hard drive and the computer. In this case, you can improve performance by increasing the speed of the hard drive connection interface.

Energy consumption is a very important characteristic for netbooks and laptops. It saves battery power by allowing devices to last longer.

Connection interface is a connection that transmits signals between the hard drive and the system, as well as protocols (the rule of exchange between them). There are several main types of connection interfaces - SATA 2, IDE, SATA, and so on.

Random access time- the time it takes for the hard drive to perform read-write operations on any part of the magnetic disk.

Noise level- the sound that is created by the hard drive when it is working. This sound consists of spindle rotation noise and positioning noise. A hard drive with a noise level of 26 decibels and below is considered quiet.

Impact resistance- resistance of the hard drive to pressure surges or impacts.

Features of hard drives for laptops

A laptop is a computer, therefore, the components of a laptop and a computer are identical. But due to the smaller size, as well as energy saving and heat dissipation, notebook hard drives have some peculiarities.

A laptop has a very limited space for devices inside the case, which makes the hardware for laptops smaller than for desktops. For example, 3.5 "hard drives are used for desktop systems, while for laptops, the diameter of a hard drive is 2.5" or less. This decrease also affects the volume, 3.5 "platters hold more data than 2.5" platters.

The typical 1.8-inch drive connector is IDE, although SATA-based hard drives have already begun to appear, like desktop computers.

In order to save energy and increase the stability of operation, drives with a lower speed are used. Winchesters will also turn off after some time. All this makes laptop hard drives more economical, but also slower.

In the vast majority of laptops, unlike stationary systems, you can install only one hard drive, but now this drawback is easily eliminated by purchasing an external drive - a hard drive connected via a USB interface. Companies producing hard drives for laptops: Samsung, Western Digital, Seagate, Toshiba and others.

external HDs

Today there are several methods for connecting external devices. There are hard drives that plug into the USB port, which are mainly used to exchange information with cameras and other mobile devices. Due to the low bandwidth of this bus, such disks will not be able to match the speed of data exchange and performance with internal devices.

Preventing and troubleshooting hard drives

All breakdowns of hard drives can be divided into those that occurred through the fault of the user or the manufacturer. The first includes such malfunctions that have arisen due to careless and improper use: various breakdowns as a result of falling laptop, downloading and installing malicious software, getting insects inside, spilling liquid and other violations of the rules for using hard drives. If such problems arise, you need to contact the service center. If you have no experience with hard drives, then it is better to entrust this business to professionals, this will save you from losing personal data.

In the event of liquid ingress or malfunctions after an impact, it is better to immediately take the laptop to a service center for diagnostics, because the consequences of such damage can unpredictably affect the operation of your device.

The second category is made up of breakdowns of the hardware or logical structure of the disks. Such damage can be divided into physical, due to external factors, damage to the disk surface, malfunctioning electronics, reading and writing errors. In most cases, after these damages, the disc can no longer be repaired, because after the impact, the engine breaks down or other critical parts of the device structure break down. It is best to take such a device to a service center for diagnostics.

Dust ingress and overheating will usually damage the disc surface. Such a disk will not be visible to the system; during its operation, it will be possible to hear the characteristic knock of the heads. In such a situation, repairs at a service center are possible. It happens by turning off the heads that read the defective surfaces and transferring all the necessary information to a new disk. The whole process is quite complicated and should be carried out by experienced specialists using special equipment, it is strongly not recommended to disassemble the hard drive at home if you do not have sufficient knowledge for this.

Sometimes damage to the surface leads to failure of the heads. This problem can also arise on its own. Its sign is the knocking of heads during the operation of the hard drive, which is especially noticeable during the read-write operation. Also, the hard drive may not be detected by the computer. Such problems arise from overheating of the hard drive or mechanical shock. The repair in this case is completely similar to the repair of the damaged surface.

Damage to the control board or other electronics is caused by short circuits, power surges, or spills. With such malfunctions, the hard drive does not make any sounds and is not detected by the system. Luck can play a decisive role here. In case of some malfunctions, you should immediately change the device; at best, you can restore some of the information. Sometimes it will be enough to replace an inexpensive board.

Read-write problems are the most common. They manifest themselves in the appearance of damaged blocks on the hard drive that cannot be read, violate the integrity of the data and can lead to their loss. Usually, such errors occur due to problems with the disk surface, although they can also arise as a result of problems with the controls. Errors can also be diagnosed at home using special software, but data recovery is best done at a service center.

If the disk is not detected by the system, or the volume is incorrectly determined, then, most likely, the service information on the disk surface or in the ROM is damaged. If problems have occurred in the ROM, then it would be more correct to immediately contact the service center and carry out the firmware or replacement of the ROM chip. In case of data loss due to surface damage, the service data is simply overwritten to other undamaged areas.

Malfunctions of the drive itself or a seizure of the spindle are caused by an impact. The disc begins to quietly buzz or tap. In the event of such damage, repair is not possible.

How to use the hard drive correctly

In order for your drive to serve you for a long time and reliably, you must adhere to the following rules:

Handle notebooks with care to avoid falls and other damage.
Update yours constantly. Do not visit questionable sites and do not run questionable programs.
Defragment and check your hard drive monthly.
Store all important data in the form of backups on external media, because the cost of creating a document can significantly exceed the cost of buying a new hard drive.
It is not necessary to fill up the hard disk completely, always leave a certain amount of free space.
Do not do frequent full formatting of the hard drive, formatting is designed for a maximum number of times.
You cannot abruptly change the position of a working hard drive in space.

These tips will help protect your hard drive from damage and save you time and money.

Favorite movies, music, family photos, videos from important life events, e-books, work documents - and this is not all that is stored on the computer of a modern person. A moment comes when there is too much information, and the built-in PC memory can no longer accept a single megabyte. It is then, most often, the need arises to purchase an external drive. written in a dedicated article on our blog.

What is a hard drive for?

But memory congestion on a personal computer is far from the only reason for purchasing a hard drive. An external hard drive is needed in many other cases as well. In which ones - we will find out further.

To offload the computer. Do you like to save all the movies you like? If there is no more space left on your PC, then it's time to pick up an external drive. It will unload the built-in memory of the computer. This is especially important if the PC hard drive is completely loaded with information. It is no secret that in this case the computer loses its performance. Gamers can use an external hard drive for games - installations, saves, etc.
To store important information. Many users are familiar with the situation when the hard drive on the computer broke down and all the information that was on the PC disappeared beyond recovery. No equipment is insured against breakdowns, so it is important to protect yourself from such a risk. To do this, it is worth transferring all the valuable information to an external drive.
For information mobility. If you need to constantly have access to a large amount of information from different computers, then an external drive is ideal. An external drive will be especially useful for work. Archives of documents can be stored on the disk, allowing you to always have quick access to them.

Benefits of using hard drives

Some users may wonder why a modern person needs an external drive if cloud storage exists. Still, external storage has its advantages over the "clouds":

You will always have access to information on your hard disk regardless of the presence of the Internet.
The speed of working with information from disk is much higher than with cloud resources. Modern hard drives are capable of recording large amounts of data at incredible speeds.
The disk guarantees reliable protection of personal data. There is always a risk of account hacking and personal information leakage. If you do not want any information to be on the network, then it is better to store it on an external drive. But don't forget to also take care of protecting your hard drive from unwanted access.

How do I choose an external hard drive?

Hard drives from a wide variety of manufacturers with a wide variety of specifications can be found on the market today. In order not to be mistaken in choosing a device, you should pay attention to its following parameters:

Memory size. The choice of volume depends on the purpose for which you purchase the device. Obviously, for storing movies, photos and video materials, it is worth choosing large disks - from one terabyte. 500 GB may be sufficient for storing work files. At the same time, a device with such a memory capacity will differ in more compact dimensions and lighter weight, which makes it very mobile.
Device security. If it will be used to store important or even confidential information, then it is worth choosing devices with an increased level of security. The rating of external hard drives in terms of reliability includes devices from such manufacturers - Hitachi, Seagate, Toshiba, Fujitsu, Western Digita and others.
Dimensions. If you often need to carry a hard drive with you, then it would be wise to opt for compact models. The best external hard drives of 2017 are small and large enough. But it is worth considering that the cost of such devices will be appropriate.

In our online gadgets store GSM-ka you will find reliable hard drives, useful, multifunctional smartphones and tablets. Choose modern gadgets and make your life easier!