Internal hdd, what is it, what is it for, what types is it divided into and how to choose the right hard drive for your computer based on the parameters. What is HDD (hard disk drive)? All about the hard drive

The hard drive is almost one of the most important elements of a modern computer. Since it is designed primarily for long-term storage of your data, this can be games, movies and other large files stored on your PC. And it would be a shame if it could suddenly break down, as a result of which you could lose all your data, which can be very difficult to recover. And in order to properly operate and replace this element, you need to understand how it works and what a hard drive is.

In this article you will learn about the operation of a hard drive, its components and technical characteristics Oh.

Typically, the main elements of a hard drive are several round aluminum platters. Unlike floppy disks (forgotten floppy disks), they are difficult to bend, hence the name hard disk. In some devices they are installed non-removable and are called fixed (fixeddisk). But in ordinary desktop computers and even some models of laptops and tablets can be replaced without problems.

Figure: Hard drive without top cover

The note!

Why hard disks sometimes called a Winchester and what they have to do with firearms. Sometime in the 1960s, IBM released what was then a high-speed hard drive with development number 30-30. Which coincided with the designation of the famous Winchester rifled weapon, and therefore this term soon became entrenched in computer slang. But in fact, hard drives have nothing in common with real hard drives.

How does a hard drive work?

Recording and reading of information located on the concentric circles of the hard disk, divided into sectors, is carried out using universal write/read heads.

Each side of the disk has its own track for writing and reading, but the heads are located on a common drive for all disks. For this reason, the heads move synchronously.

YouTube Video: Open Hard Drive Operation

Normal drive operation does not allow contact between the heads and the magnetic surface of the disk. However, if there is no power and the device stops, the heads still fall onto the magnetic surface.

During operation of the hard drive, a small air gap forms between the surface of the rotating platter and the head. If a speck of dust enters this gap or the device is shaken, there is a high chance that the head will collide with the rotating surface. A strong impact can cause the head to fail. This output may result in several bytes being corrupted or the device being completely inoperable. For this reason, in many devices the magnetic surface is alloyed, after which a special lubricant is applied to it to cope with periodic shaking of the heads.

Some modern drives use a loading/unloading mechanism that prevents the heads from touching the magnetic surface even if the power is lost.

High and low level formatting

Using Formatting high level allows the operating system to create structures that make it easier to work with files and data stored on the hard drive. All available partitions (logical drives) are supplied boot sector volume, two copies of the file allocation table, and the root directory. Through the above structures, the operating system manages to distribute disk space, tracking the location of files, as well as bypassing damaged areas on the disk.

In other words, high-level formatting comes down to creating a table of contents for the disk and file system(FAT, NTFS, etc.). “Real” formatting can only be classified as low-level formatting, during which the disk is divided into tracks and sectors. Using the DOS FORMAT command, a floppy disk undergoes both types of formatting at once, while a hard disk undergoes only high-level formatting.

In order to produce low level formatting on your hard drive, you must use special program, most often provided by the disc manufacturer. Formatting floppy disks using FORMAT involves performing both operations, while in the case of hard disks, the above operations should be performed separately. Moreover, the hard drive undergoes a third operation - the creation of partitions, which are a prerequisite for using more than one on one PC. operating system.

The organization of several partitions makes it possible to install on each of them its own operating infrastructure with a separate volume and logical drives. Each volume or logical drive has its own letter designation (for example drive C,D or E).

What does a hard drive consist of?

Almost every modern hard drive includes the same set of components:

disks(their number most often reaches 5 pieces);

read/write heads(their number most often reaches 10 pieces);

head drive mechanism(this mechanism sets the heads to the required position);

disk drive motor(a device that causes disks to rotate);

air filter(filters located inside the drive housing);

printed circuit board with control circuits(through this component the drive and controller are managed);

cables and connectors(HDD electronic components).

A sealed box - HDA - is most often used as a housing for disks, heads, head drive mechanism and disk drive motor. Usually this box is a single unit that is almost never opened. Other components not included in the HDA, which include configuration elements, printed circuit board and front panel, are removable.

Automatic head parking and control system

In the event of a power failure, a contact parking system is provided, the task of which is to lower the bar with the heads onto the discs themselves. Regardless of the fact that the drive can withstand tens of thousands of ascents and descents of the read heads, all this must happen in areas specially designated for these actions.

During constant ascents and descents, inevitable abrasion of the magnetic layer occurs. If the drive is shaken after wear and tear, damage to the disk or heads is likely to occur. To prevent the above troubles, modern drives are equipped with a special loading/unloading mechanism, which is a plate that is placed on the outer surface hard drives. This measure prevents the head from touching the magnetic surface even if the power is turned off. When the voltage is turned off, the drive automatically “parks” the heads on the surface of the inclined plate.

A little about air filters and air

Almost all hard drives are equipped with two air filters: a barometric filter and a recirculation filter. What distinguishes the above filters from replaceable models used in older generation drives is that they are placed inside the case and are not expected to be replaced until the end of their service life.

Old disks used the technology of constantly moving air in and out of the case, using a filter that needed to be changed periodically.

The developers of modern drives had to abandon this scheme, and therefore the recirculation filter, which is located in the sealed HDA case, is used only to filter the air inside the box from the smallest particles trapped inside the case. Regardless of all precautions taken, small particles still form after repeated landings and takeoffs of the heads. Taking into account the fact that the drive housing is sealed and air is pumped inside it, it continues to function even in a heavily polluted environment.

Interface connectors and connections

Many modern hard drives are equipped with several interface connectors designed to connect to the power source and to the system as a whole. As a rule, the drive contains at least three types of connectors:

interface connectors;

power supply connector;

ground connector.

The interface connectors deserve special attention, since they are designed for the drive to receive/transmit commands and data. Many standards do not exclude the possibility of connecting several drives to one bus.

As mentioned above, HDD drives can be equipped with several interface connectors:

MFM and ESDI- extinct connectors used on the first hard drives;

IDE/ATA- a connector for connecting storage devices, which has long been the most common due to its low cost. Technically, this interface is similar to the 16-bit ISA bus. The subsequent development of IDE standards contributed to an increase in data exchange speed, as well as the emergence of the ability to directly access memory using DMA technology;

Serial ATA- a connector that replaced IDE, which is physically a unidirectional line used for serial data transfer. Being in compatibility mode is similar to the IDE interface, however, the presence of a “native” mode allows you to take advantage of an additional set of capabilities.

SCSI- a universal interface that was actively used on servers for connecting HDDs and other devices. Despite good technical performance, it has not become as widespread as IDE due to its high cost.

SAS- serial analog SCSI.

USB- an interface that is necessary for connecting external hard drives. Information exchange in this case occurs via the USB Mass Storage protocol.

FireWire- a connector similar to USB, required for connecting an external HDD.

Fiber Channel-interface used by high-end systems due to high data transfer rates.

Hard drive quality indicators

Capacity- the amount of information the drive can hold. This figure in modern hard drives can reach up to 4 terabytes (4000 gigabytes);

Performance. This parameter has a direct impact on response time and average information transfer speed;

Reliability– an indicator determined by the mean time between failures.

Physical Capacity Limits

The maximum amount of capacity used by a hard drive depends on a number of factors, including the interface, drivers, operating system and file system.

The first ATA drive, released in 1986, had a capacity limit of 137 GB.

Different BIOS version also contributed to a reduction in the maximum capacity of hard drives, and therefore systems built before 1998 had a capacity of up to 8.4 GB, and systems released before 1994 had a capacity of 528 MB.

Even after solving the problems with the BIOS, the capacity limitation of drives with an ATA connection interface remained; its maximum value was 137 GB. This limitation was overcome through the ATA-6 standard, released in 2001. This standard used an expanded addressing scheme, which, in turn, contributed to an increase in storage capacity to 144 GB. Such a solution made it possible to introduce drives with PATA and SATA interfaces, whose storage capacity is higher than the specified limit of 137 GB.

OS restrictions on maximum volume

Almost all modern operating systems do not impose any restrictions on such an indicator as the capacity of hard drives, which cannot be said about earlier versions of operating systems.

For example, DOS did not recognize hard drives whose capacity exceeded 8.4 GB, since access to the drives in this case was performed through LBA addressing, while in DOS 6.x and earlier versions only CHS addressing was supported.

There is also a hard disk capacity limitation when installing Windows 95. The maximum value of this limitation is 32 GB. In addition, updated Windows versions 95 only supports the FAT16 file system, which, in turn, imposes a 2 GB limit on partition sizes. It follows from this that if you use a 30 GB hard drive, it must be divided into 15 partitions.

Windows 98 operating system limitations allow the use of larger hard drives.

Characteristics and parameters

Each hard drive has a list of technical characteristics, according to which its usage hierarchy is established.

The first thing you should pay attention to is the type of interface used. Recently, every computer has begun to use SATA.

Second no less important point- volume free space on your hard drive. Its minimum value today is only 80 GB, while the maximum is 4 TB.

Another important characteristic when purchasing a laptop is the hard drive form factor.

The most popular in this case are models whose size is 2.5 inches, while in desktop PCs the size is 3.5 inches.

You should not neglect the spindle rotation speed, the minimum values ​​are 4200, the maximum is 15000 rpm. All of the above characteristics have a direct impact on the speed of the hard drive, which is expressed in MB/s.

Hard drive speed

Speed ​​indicators are of no small importance hard drive, which are determined:

Spindle speed, measured in revolutions per minute. Its task does not include directly identifying the real exchange speed; it only allows you to distinguish a faster device from a slower device.

Access time. This parameter calculates the time spent by the hard drive from receiving a command to transmitting information over the interface. Most often I use the average and maximum values.

Head positioning time. This value indicates the time it takes for the heads to move and set up from one track to another track.

Bandwidth or disk performance during sequential transfer of large amounts of data.

Internal data transfer rate or the speed of information transmitted from the controller to the heads.

External baud rate or the speed of information transmitted via the external interface.

A little about S.M.A.R.T.

S.M.A.R.T.– a utility designed to independently check the status of modern hard drives that support the PATA and SATA interfaces, as well as those running in personal computers with an operating system Windows system(from NT to Vista).

S.M.A.R.T. calculates and analyzes the state of connected hard drives at equal intervals of time, regardless of whether the operating system is running or not. After the analysis has been carried out, the diagnostic result icon is displayed in the right corner of the taskbar. Based on the results obtained during S.M.A.R.T. diagnostics, the icon may indicate:

For the excellent condition of every hard drive connected to the computer that supports S.M.A.R.T. technology;

The fact that one or more health indicators do not meet the threshold value, while the Pre-Failure / Advisory parameters have a zero value. The above state of the hard drive is not considered pre-failure, however, if this hard drive contains important information, it is recommended to save it on another medium as often as possible or replace the HDD.

The fact that one or more status indicators do not meet the threshold value, while the Pre-Failure / Advisory parameters have an active value. According to hard drive developers, this is a pre-emergency state, and it is not worth storing information on such a hard drive.

Reliability factor

An indicator such as data storage reliability is one of the most important characteristics of a hard drive. The failure rate of a hard drive is once every hundred years, from which we can conclude that HDD is considered the most reliable source of data storage. At the same time, the reliability of each disk is directly influenced by the operating conditions and the device itself. Sometimes manufacturers supply the market with a completely “raw” product, and therefore neglect backup and you cannot completely rely on the hard drive.

Cost and price

Every day the cost of HDD is becoming less and less. For example, today the price of hard ATA drive for 500 GB is an average of $120; in comparison, in 1983, a hard drive with a capacity of 10 MB cost $1,800.

From the above statement we can conclude that the cost of HDDs will continue to fall, and therefore in the future everyone will be able to purchase fairly capacious disks at reasonable prices.

What is HDD, hard drive and hard drive - these words are different widely used terms for the same device that is part of the computer. Due to the need to store information on a computer, information storage devices such as a hard drive appeared and became an integral part of personal computer.

Previously on the first computers information was stored on punched tapes - this is cardboard paper with holes punched in it; the next step of man in the development of a computer was magnetic recording, the principle of operation of which is preserved in today's hard drives. Unlike today's terabyte HDDs, the information to be stored on them numbered tens of kilobytes, which is insignificant compared to today's information.

Why do you need a HDD and its functionality?

HDD is a computer's permanent storage device, that is, its main function is long-term data storage. HDD, unlike RAM, is not considered volatile memory, that is, after turning off the power from the computer, and then, as a result, from the hard drive, all information previously stored on this drive will certainly be preserved. It turns out that the hard drive serves as the best place on the computer for storing personal information: files, photographs, documents and videos will obviously be stored on it for a long time, and the stored information can be used in the future for your needs.

ATA/PATA (IDE)- this parallel interface serves not only to connect hard drives, but also disk reading devices - optical drives. Ultra ATA is the most advanced representative of the standard and has possible speed data usage up to 133 megabytes per second. This method of data transfer is considered very outdated and today is used in outdated computers; IDE connectors can no longer be found on modern motherboards.

SATA (Serial ATA)- is a serial interface, which has become a good replacement for the outdated PATA and, unlike it, it is possible to connect only one device, but on budget motherboards there are several connectors for connection. The standard is divided into revisions that have different data transfer/exchange rates:

• SATA has a data transfer speed of up to 150 Mb/s. (1.2 Gbit/s);
• SATA rev. 2.0 - in this revision, the data exchange speed in comparison with the first SATA interface has increased 2 times to 300 MB/s (2.4 Gbit/s);
• SATA rev. 3.0 - data exchange for the revision has become even higher up to 6 Gbit/s (600 MB/s).

All of the above-described connection interfaces of the SATA family are interchangeable, but if you connect, for example, a hard drive with a SATA 2 interface to the connector motherboard SATA, data exchange with the hard drive will be based on the highest revision, in this case SATA revision 1.0.

Internal hdd what is it

Hard Disk Drive, abbreviated hdd, is one of the most important, most expensive and most complex components of a modern computer. HDD is designed for long-term storage of large amounts of information used by a PC, operating system files and programs. It is from the hard drive, or as computer scientists call it “screw,” that the operating system is loaded. If a disk fails, you have to spend a lot of money buying a new hard drive. But most importantly, all information will be lost if a backup copy has not been created in advance.

Hard drives are:
— external — External HDD;
— internal — Internal HDD.

Features of choosing internal hdd.

Inside the case system unit internal hdd is what it is and what to look for when purchasing. Hard drives are designed to store information and load the operating system. To hard drives that provide reliable and operational work operating system, there are increased requirements. The requirements for internal hdd, whose main task is to store and process information, are completely different.
The problem of choice is solved by the ability to install several hard drives in modern PCs, each of which performs its own tasks.

Internal internal hdds are available for personal computers and laptops. They differ in size:
— 3.55 inches for PC;
- 2.5 inches - for a laptop.

Hard drive parameters.

The need to purchase a new device arises in two cases: the capacity of the working hard drive is not enough for normal operation of the computer or the old drive has failed.
The hard drive is one of the most unreliable PC components, as it combines a complex mechanical part and electronic boards. In addition, mechanics cannot withstand physical impact: vibration, shaking, shock. How do you know if your hard drive is bad? If there are problems with the device, the computer may reboot at any time, freeze during operation, or turn off.
What is better to do: buy a new hard drive or repair the old one? The answer is clear: it is easier and cheaper to purchase a new internal hdd. These devices are rarely repaired.

When choosing a hard drive, you need to consider three main parameters:

1. Interface type.
Your drive must be fully compatible with motherboard. There are different interface options: SCSI, SATA, IDE and SAS. An IDE connection is only suitable on older computers. Currently, they are most often used different versions SATA. Modern interfaces for connecting drives allow you to work with files much faster.

2. Performance.
The speed of the disk is affected by the spindle rotation speed. There are standard rotation speeds: from 5400 to 7200 rpm. How to make the right choice? 5400 rpm is enough to store data; if you need to install systems and programs, you need to select a screw with parameters of -7200 rpm. "Green" drives, having 5400 rpm, are characterized by low energy consumption and quiet operation. More revolutions provide faster read and write speeds.
There are models that have speeds from 10,000 to 15,000 rpm. Used exclusively for servers and professional purposes.

The intermediate memory buffer - cache, also affects the performance of the internal hdd. Cache values ​​range from 8 to 64 MB. The larger the cache size, the faster the screw:
— 8 MB is enough for 500 – 750 GB;
— 16 MB – for 1 TB.

3. Capacity.
HDD capacity is measured by the amount of information volume that fits on the device. The first internal hdds had a capacity of only 60 MB. The smallest hard drive capacity today is 160 GB. Modern devices most often have value ranges from 200 to 500 GB. The size of some devices can reach up to 3 TB.
When choosing, focus on your needs and financial capabilities: the higher the capacity, the more information will fit, but the price also increases significantly.

The last two parameters are quite difficult to combine on one device. Therefore, disks are conventionally divided into:
- universal;
- capacious;
- fast.

When choosing an internal hdd, you need to decide on the functional tasks. If your computer has one hard drive, then it is better to choose universal models that are manufactured with an optimal ratio of speed and capacity. A fast hard drive is used as a system disk. To store large amounts of information, high-capacity disks are chosen. If the choice is made correctly, the entire system will work in a balanced manner and without failures.

Advantages and disadvantages different types internal hdd.

Universal ones have a fairly high degree of reliability and do not have serious drawbacks. Fast hard drives, in addition to being fast, are also highly reliable. Disadvantages include rapid heating and noise.
Capacitive internal hdds are considered the most unreliable, especially models with a capacity exceeding 1 TB. The advantages of such hard drives are reduced noise, low power consumption and moderate heating.

Features of choosing a hdd for a laptop.

Laptops do not need fast or capacious internal hdds. It is best to choose a universal hard drive with balanced characteristics.

The main differences between internal hdd for a laptop:
1. The devices are smaller and more compact.
2. Hard drives are installed with a spindle speed of 4200 to 5400 rpm, which ensures low power consumption.
3. HDD capacity in laptops is no more than 200 GB.

How to install an internal hard drive in a laptop

You can replace the hard drive in your laptop yourself. Usually this does not cause any difficulties. The main condition is caution. In all laptops, the internal hdd is located in a metal frame inside the case. The new hard drive is inserted into the same frame.
A prerequisite for replacement is to check the compatibility of the new internal device with the laptop motherboard. If the newly purchased hard drive has an inappropriate connector, it will not be possible to install it. Therefore, before purchasing, study the instructions, clarify the technical parameters, and determine the type of interface. Most often, SATA and IDE interfaces are used to connect hdds, which differ in the width of the cable and connector.

Currently, internal hdds, which are installed in laptops, are practically not inferior in performance and speed to hard drives in PCs. Moreover, the speed of access to information can always be increased by connecting an additional external drive.

Manufacturers.

Today there are five main brands in the lead:: Seagate, Western Digital, Toshiba, Hitachi, Samsung. There are, of course, models from other brands. But, as a rule, these are licensed “repetitions” of already well-known models.
Define best brand It’s not at all easy, just like saying which hard drive will last longer. Basically, all drives are quite reliable and have almost the same characteristics. But Seagate and Western Digital are still considered the most reliable companies.

Reviews on various forums will help you make the right choice. Type the drive brand into a search engine and read customer reviews. You should not trust one site or forum. Use multiple sources to avoid wasting money and losing valuable information. Choose wisely. It is important to remember: you need to purchase hard drives only from a trusted seller, and not at the market.

HDD is a data storage device - a hard magnetic disk drive. “HDD” is an abbreviation for the English phrase Hard Disk Drive. Other names for HDD: hard drive, hard drive, HDD, screw, hard, tin, tin.

What is HDD for?

HDD is used to store information. The information located on the hard drive is called data. The data on the disk is organized using a file system and is represented by files.

HDD is computer memory. Don't confuse it with RAM. Hard disk - non-volatile memory, RAM- volatile.

The hard drive is now the main storage device, and if you have a computer, then you have a screw.

Operating principle of HDD

Hard drives, that is, HDDs, work similarly to a device that everyone has long forgotten about - a “player”, with a rotating disk and a needle for playing music. The conversion elements (read/write heads) used in hard drives are similar to the read/write heads that are used in VCRs and stereo cassette recorders to access information on magnetic media.

Hard drives store information on a rotating metal or glass plate coated with magnetic material. As a rule, the disk consists of several plates connected by a common rod - a spindle. Each plate is something like a vinyl record with a recording that is played by a turntable. Information is usually stored on both sides of the plate.

As the disk spins, an element called the head reads or writes binary data onto the magnetic media. Information is written to the disk using any encoding method, of which there are a great many. The encoding method and recording density are determined by the disk controller.

Without delving further into the description of the operating principle of an HDD, we can say that a hard drive is, in fact, a super player with a bunch (or maybe just one) of gramophone records inside. Although, of course, in terms of the complexity of the device, the player was not lying around with it.

The past and future of HDD

The very first HDD was developed by IBM in the early 70s.

In 1983, with the release of the first IBM PC/XT computer, a hard drive from Seagate Technology appeared in the lives of thousands of newly minted, still wild users. The early hard drive interface, developed by Alan Shugart (founder of Seagate Technology), was the de facto standard for HDDs for many years. Subsequent developments by Seagate formed the basis for the ESDI and IDE interfaces. Shugart also developed the SCSI interface, which is now used in many modern computers.

By the way, Seagate hard drives are now the best-selling in Europe. And who in Russia doesn’t know the famous Barracudas?

The most important direction in the development of hard drive technology has always been to increase their (storage) capacity. Progress in this area is particularly driven by ever-increasing demands software. Increasing the capacity of drives is possible either by increasing the size of the drives themselves or by increasing the data storage density. The limit for increasing HDD sizes has been reached, the limit for data storage density has not yet been reached. But it won't be long.

Need to know

1. HDD is a complex contraption for storing information

2. The hard drive is short-lived and is unlikely to last more than three years with constant use.

3. It is extremely undesirable to carry a hard drive (somewhere), twirl it in your hands, or even remove it from the computer case. Winchester is very sensitive to vibration!

4. Internal organization HDD is very complex. If you once went to a circle of young radio amateurs, this does not mean at all that you can now repair hard drives. Repairing hard drives requires more than just a soldering iron!

5. Those who like to tinker with hardware need to remember that by opening the HDA of the disk, you thereby put an end to both the information and the hard drive itself

6. In terms of storage security, storage media can be arranged in this order (with increasing risk of data loss): head, paper, hard drive. Do not store important information on the HDD! And if you have to, always make backups!

7. If the information on your hard drive is unavailable for some reason, do not try to restore it! Most likely, you will only completely destroy it - it is better to turn to professionals. Data recovery is no big deal!

8. The word “HDD” is a dirty word and is not used in polite society; it characterizes something (to put it mildly) unreliable, short-lived and disgusting