A computer's hard drive (aka HDD (Hard Disk Drive), aka a hard drive, aka a magnetic drive, aka a “screw” and a “hard”). Non-volatile storage of our collections of films and other files :) “Non-volatile” in this case means that all stored information remains on the hard drive after the computer is turned off.

What functions (besides directly storing our data) does it perform? HDD computer? We install all our software on it. Our most important program (set of programs) - the operating system - is also installed on it. Without an operating system, a computer is a pile of expensive hardware, you understand :) The computer’s hard drive also very often performs another important function, being (if necessary) an extension for random access memory computer. Especially if there is a shortage of the latter.

Let me explain with an example: Software, running on a computer and performing some task, requires 300 megabytes of memory to work, but only 250 are free at the moment (for example). The operating system makes a cunning move: it begins to “dump” data that has not been requested for a long time from RAM onto the computer’s hard drive, thus freeing up space in RAM for the needs of the running program.

To be fair, it is worth noting that the overall speed of completing any task in this case begins to drop catastrophically. And this is logical. After all, memory speed and hard drive there is no comparison. The computer’s hard drive is much slower, and the more data the operating system has to “dump” onto it from fast RAM, the more noticeable the overall performance drop will be.

If we take this process to the extreme, then a situation is possible in which almost any user action will be accompanied by frantic attempts by the operating system to free up another section of RAM and rewrite the next portion of data to the hard drive. This can be visually determined by the constantly blinking red hard drive operation indicator on the front panel of the computer. The result is a very slow response of the system to any user actions (often reminiscent of freezing) and a constantly blinking red light (LED) of the hard drive on the front panel of the case.

The situation described above is often typical for computer systems with insufficient RAM. Let's put it more precisely this way: with insufficient memory for the tasks that are assigned to it :)

A few words about the misconception associated with a computer hard drive: many people believe that there is a vacuum inside it, but this is not so. During the production cycle, the internal closed space of the disk (hermetic block) is filled with air with a pressure of one atmosphere to create the effect of an “air cushion” between the “pancakes” and the read-write magnetic heads.

The requirements for air purity inside the hermetic unit (hermetic zone) are quite strict. There should be no dust particles larger than 0.3 microns (micrometer or micron) present. For comparison, the average thickness of a human hair is 40 microns. Now, I think it is clear that a computer hard drive cannot be disassembled at home.

Inside the hard drive there is a spindle (axis), on which one or more magnetic disks “pancakes” are strung, which are located one above the other. Under this structure there is a motor that spins the spindle to the required speed.

The magnetic heads that perform read-write operations in the computer hard drive are combined into a magnetic head unit (MMG), which simultaneously moves them all and places them above the desired cylinder of the hard drive. The BMG drive is called a positioner.

Now let's "look under the cap" :) So - a computer hard drive without a protective cover.

What we see here:

• 1 - spindle that spins the hard drive plate.
• 2 - the magnetic plate of the hard drive itself - “damn” (where all our information is recorded)
• 3 - read-write head, which, moving a few microns from the surface of the disk, performs read-write operations.

If we completely disassemble the computer’s hard drive, we will see this picture:

The picture is clickable.

There is another class of devices - external hard disks. This is, in fact, structurally the same hard drive, only more compact and hermetically sealed in an anti-shock shell. Such drives are connected to the computer via a USB interface and act as “large flash drives” :)

There is an opinion that there is a vacuum inside the disk, but this is not so. Each computer hard drive has a special micro-hole, under which (on the inside) there are several filters, they protect the hermetic zone of the hard drive from dust particles from the air entering it.

Nowadays, solid-state computer drives are increasingly becoming fashionable: SSD - solid-state drive. You can read about my personal acquaintance and experience with SSD drives in a separate article on our website.

Why do you need a hard drive?
The job of a hard drive is to store data. Everything on your computer is located on your hard drive. And we're not just talking about documents, images and videos. Your programs, settings, and even your operating system are all stored on your computer's hard drive.

And all this can be lost in one moment if the disk is damaged. This is the reality. This is why most people create a system Reserve copy. They purchase another hard drive and copy all their important files onto it.

What size hard drive do you need?
Everything that can be stored on your hard drive has its own size. Text files They usually take up little space, images take up more, music takes up even more, and the heaviest ones are video files.

The hard drive resembles a scale. He does not “see” the qualitative difference between the stored data; only their weight (size) is important to him. But its hard drive measures not in meters and kilograms, but in megabytes (MB), gigabytes (GB) and terabytes (TB).

Roughly speaking, there are 1 million bytes in a megabyte, 1 billion in a gigabyte, and 1 trillion bytes in a terabyte.

What does this mean for users?

If you frequently need to transfer files from one computer to another, or only want to back up some files, a small hard drive (such as a 500GB Expansion Series drive) will do just fine.

If it is necessary to do backup copy your entire computer, or even multiple computers, or if you have a lot of video and audio files, you'll need a larger drive (such as a 1 TB or larger Backup Plus desktop drive).

Which computer needs a hard drive: PC or Mac?
Any Seagate drive is compatible with PC and Mac computers. Some discs are sold already formatted to work with a specific type of computer, but they can always be reformatted as necessary.

IMPORTANT NOTE! Reformatting a disk erases every single file on it. Therefore, before you perform this action, be sure to save copies of the files to a safe location.

But using one drive with both PC and Mac computers is a rather difficult task. In short, they are poorly compatible. In a little more detail, the possibilities for such use are very limited: it will be possible to perform only some specific operations in some special conditions. For more information on this topic, see.

What types of connections are there? hard drives?
There are four main ways connecting hard disk to the computer.

1. USB
   This is the most common type of connection. It does not require installation of any programs. Just connect the cable. The computer will recognize the drive and you will be able to read and save files almost immediately.
2. FireWire
   Featuring a plug-and-play feature like USB, Firewire 800 provides high data transfer speeds, making it popular among users who frequently transfer video files from one computer to another.
3. SATA
   This is the standard connection type for internal hard drives. It allows you to transfer files of any format at the highest speed.
4. eSATA
   A less common high-performance connection type that is most often used in PC computers. With an eSATA connection, files are transferred at a speed that closely matches the data transfer speed of the internal hard drive.

What does it mean speed hard disk?
When you turn on your computer, open a file, listen to a song, or perform any other action, you are using your hard drive. Rotating plates are located inside the disk. The higher the speed of their rotation, the faster computer finds the file you need.

Therefore, a 7200 RPM drive transfers data faster than a 5400 RPM drive. Your performance will be affected differently depending on the type of drive you are using. If the drive is external, you will hardly notice the difference. If the disk is internal, the difference will be felt - and the more clearly the larger the files or applications you use.

Which drive to choose: internal or external?
The internal drive allows data transfer at higher speeds. External drive has greater flexibility and the ability to expand storage resources.

Each option has its own advantages and disadvantages.

Internal drives require physical installation, while not every user will dare to open the computer case. But in this case, files and programs are stored directly on the computer and are available at any time.

External hard drives are connected to the computer using a plug-in cable, such as portable disk Backup Plus Portable, or accessed via Wi-Fi, as in the case of the Wireless Plus drive. This allows you to take necessary files take them with you, transfer them to other computers, or instantly and without unnecessary technical difficulties increase the storage space on your computer or network.

How much information can be stored?

Here are some average indicators that will help you get an idea of ​​the storage capabilities on hard drives.

* Average file size when using the camera's highest resolution JPEG format. The actual number of images that can fit on your hard drive may vary and will depend on the camera model and the characteristics of the scene being photographed.

† Two-hour DVD-quality movies.

††One gigabyte (GB) hard capacity disk is assumed to be one billion bytes. Available capacity may vary depending on operating environment and formatting. Number of stored files for different applications This is for example only. Actual Quantitative Indicators depend on many factors, including file size and format, tools and software applications used.

Many of you know that all information on a computer, presented in the form of files and folders, is stored on the hard drive. And here, what is a hard drive and what it is intended for, not many will answer correctly. It is very difficult for people far from programming to imagine how information can be stored on some piece of hardware. This is not a box or a piece of paper on which this very information can be written down and hidden in the box. Yes, a hard drive is not a box with a letter.

A hard disk (HDD, HMDD - from the English hard (magnetic) disk drive) is a magnetic storage medium. In computer slang it is called a “Winchester”. It is designed to store information in the form of photographs, pictures, letters, books of various formats, music, films, etc. Externally, this device does not look like a disk at all. Rather, it looks like a small rectangular iron box.

The internals of a hard drive are similar to an old vinyl record player.

Inside this metal box there are round aluminum or glass disk plates located on the same axis, along which the reading head moves. Unlike a player, the hard disk head does not touch the surface of the platters during operation.

For ease of use, the hard drive is divided into several sections. This division is conditional. This is done using the operating system or special programs. The new partitions are called logical disks. They are assigned the letters C, D, E or F. Usually installed on the C drive, and files and folders are stored on other drives so that if the system crashes, your files and folders are not damaged.

Watch a video about what a hard drive is:

Basic characteristics of hard drives

• Form factor is the width of the hard drive in inches. Standard size for desktop computer 3.5 inches, and for laptops 2.5 inches;
• Interface- V modern computers used connection to motherboard SATA of various versions. SATA, SATA II, SATA III. Older computers use the IDE interface.
• Capacity- This maximum amount The information that a hard drive can store is measured in gigabytes;
• Spindle speed is the number of spindle revolutions per minute. The higher the disk rotation speed, the better. For operating systems it is necessary to install disks of 7,200 rpm and higher, and for storing files you can install disks with lower speeds.
• MTBF– this is the average time between failures calculated by the manufacturer. The larger it is, the better;
• Random access time is the average time required for the head to position itself on an arbitrary section of the wafer. The value is not constant.
• Impact resistance is the ability of a hard drive to withstand pressure changes and shocks.
• Noise level, which the disk emits during operation is measured in decibels. The smaller it is, the better.

It already exists now SSD drives(solid-state drive in simple translation - solid-state drive), which have neither a spindle nor platters. It is a storage device based on memory chips.