When a buyer tries to assemble a computer from components on his own or just choose a hard drive for a PC, he often comes up with the concept of "RPM". What is it and is it important? RPM is not just important, but one of the key parameters of the hard drive, which must be considered first of all when choosing. Let's see in more detail that this is an RPM.
The concept
The abbreviation RPM (Rounds per minute) is literally translated into Russian as “Revolutions per minute”. This unit indicates the spindle speed of the hard disk, but the concept itself does not say anything to the average user. Hard disk RPM plays a role in system performance, and the higher the rotation speed, the faster the whole system will work. Most often, this parameter is indicated in the characteristics of the hard disk, and it is advisable to choose the one with the highest RPM between two solid media.
If you take two drives identical in all parameters, but with different spindle speeds, you can immediately notice a significant difference in system performance.
What is a spindle?
The hard disk consists of several sealed round plates that are on top of each other and covered with a layer of ferromagnetic material. There is also a read head in the housing. These plates rotate during operation using a spindle - a special rotating shaft. This shaft is driven by an electric motor. When the plates rotate, the read heads do not touch the surface of the disks, however, they are located at the closest possible distance to them. As a result, using the heads you can write and read information from solid media - disks.
For thousands of hours, the spindle stably rotates the plates with great speed, so this element must be reliable. Due to the lack of direct physical contact between the spindle and the disk, the latter can record and erase information. It is believed that on average, one disc can record and erase information 100 thousand times.
This is what the hard drive spindles look like. Of course, they may differ depending on the model of the device and the manufacturer.
So, we found out that this is an RPM. The parameter determines at what speed the plates can rotate during normal operation. In turn, this makes it possible to understand how quickly a computer system can receive information from a hard disk when accessing it. The higher the speed, the faster the data will be exchanged between the system and the disk.
How it works?
To understand more precisely that this is an RPM, you need to understand the principle of operation of the device itself. When requesting certain information, the block of magnetic heads goes to the requested track. This takes some time to search (Seek latency). After the read heads move to the desired sector, it is necessary to wait for the disks to turn so that the desired area is under the read head. This time section is called rotation delay. This parameter depends on the spindle rotation speed, and the higher it is, the lower the rotation delay will be.
Both delays (for spindle movement and disk rotation) determine the speed of system access to data. Many performance testing programs calculate this parameter and display it under the "Access to data time" lines. This allows you to determine the actual speed of the disk. This parameter directly affects the performance of the entire system. Today there are many powerful laptops that are equipped with powerful graphics cards and processors, a large amount of RAM. But at the same time, very slow hard drives with a rotation speed of 5400 revolutions per minute are used together with good hardware. As a result, all these powerful components do not work at full capacity due to the low speed of data access. So the RPM of the disk is important along with the processor frequency and the bus width of the video card.
Performance Impact of RPM HDD
Winchesters (so often called hard drives) can be in the LFF and SFF formats. Simply put, one type of disk has a format of 2.5 inches, the other - 3.5 inches. The first is often used in laptops and servers, the second - in ordinary system units. It is this type of hard drive that most often has a high spindle speed - 7200 rpm. In such models, the half-turn time is 4.2 ms, and the average search time is 8.5 ms. Therefore, the data access time will be 12.7 ms.
Note that most desktop computers use SATA hard drives. The 7200 RPM is the standard speed for these models. There are also disks with 5400 RPMs, but they are not recommended for use on modern systems, although they are cheaper. There are also disks with the parameter 10000 RPM - in such models, the search and rotation delays are about 3 ms. Such devices are most often used on gaming computers, but even they can be called obsolete. In modern desktop PCs and laptops, SSDs are increasingly being used, the principle of which is completely different. We will talk about this a bit later.
Custom RPM
There are also models on the market with spindle speeds of 15,000 rpm. As you might guess, there the delay time is even lower - about 2 ms, and the average search time is 3.8 ms. This allows you to provide access to data in 5.8 ms. Therefore, disks with large RPMs have a low search time for the necessary information, which ensures a quick exchange between the information store and the system.
However, it is important to note that when accessing large data, the performance difference between disks with large and low RPM parameters will be insignificant, since there will be no delays in access to information at all.
How to find out the spindle speed?
Defining this parameter is as simple as possible - it is always indicated on the sticker on the device itself. Just open the case of your system unit and look at the sticker. There may be many obscure parameters, but there is always one of the following lines:
- RPM HDD: 5400.
- RPM: 7200.
- RPM: 10000.
If the hard drive is hidden under the laptop case, which is quite difficult to open, then you can use the special hardware testing program.
The following are popular:
- Crystalmark
- Aida64.
- Speccy.
They are available for download from the Internet for free. By running one of these programs, you can quickly find information about the storage device. There will be displayed in detail the parameters of the hard drive. We are primarily interested in the line "Rotation Rate" and the value opposite it. In the Russian version of the Aida64 program, you need to click on "Data Storage" - "Windows Data Storage" in the left part, then select the hard disk in the upper part, after which information about it will appear from the bottom, including the line "Rotation Speed".
Disadvantages of high speed
Of course, with a high RPM, high overall system performance is ensured, but there are also disadvantages. The faster the spindle rotates, the more the disk warms up, and it works noisier. Also, such hard drives consume more electricity. However, modern technology allows you to install RPM and reduce energy consumption and noise by reducing spindle speed. At the same time, performance losses are compensated by a special data caching algorithm.
SSD as an alternative
When developing modern computer platforms, the use of hard drives with plates and a spindle is refused. Today, solid state drives are used, in which there are no moving parts at all. The "insides" of these drives are microcircuits on the board. Such devices as ordinary flash drives work, but only the performance and speed of access to data in them is very high and far exceeds the performance of standard HDD disks. In addition, they do not make noise, are very light and consume little energy. High price is the only drawback. A 1TB HDD 7200 RPM will cost less than an SSD with a capacity of 128 or 256 GB.
To draw an analogy, the difference between SSD and HDD is approximately the same as the difference between a regular DVD-ROM and a flash drive. They have already moved away from disks, and today only flash drives are mainly used.
Conclusion
When choosing a hard disk in the first place, it is important to consider the performance parameter, which is determined primarily by the spindle speed. Unfortunately, most users look at disk capacity, although this is not the most important. It is better to give preference to a hard drive with a capacity of 500 GB and a spindle speed of 7200 rpm than choosing a 1 TB drive and an RPM 5400 parameter. In general, today you need to move away from using such systems, since SSDs outperform legacy HDD devices in everything .