Type
The type to which the drive belongs. Hard drives in a broad sense again include several types of drives:
— HDD. Hard drives in the classical sense of the word are drives that record information on rotating magnetic platters. Despite the emergence of more advanced types of drives, classic HDDs still do not lose popularity due to the combination of impressive volumes and low cost. Their main disadvantages are significant weight and power consumption, as well as relatively low speed of reading and writing data.
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SSHD. Hybrid drives that combine the HDD described above and an SSD solid-state drive in one case; while the system perceives SSHD as a single device. The idea of such a combination is to increase the speed of reading and writing, while retaining the main advantage of the HDD — large volumes at a low cost. To do this, the solid state part of the SSHD acts as a high-speed clipboard between the system and the HDD; in terms of speed, such systems, although they do not reach full-fledged SSDs, are noticeably superior to traditional hard drives.
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RAID array. RAID arrays implemented as separate devices (usually external, see "Execution"). Such a device consists of several hard drives installed in one housing and combined into an array, perceived by the system as a single drive. There are several types (levels) of RAID, which differ in the way disks interact in an array and
..., accordingly, in the specifics of their application. So, in RAID 0, information is alternately written to each disk, which increases the speed of work; in RAID 1, each disk is a copy of all the others, which gives maximum fault tolerance, etc. Detailed information on RAID levels can be found in special sources. Also note here that buying a RAID array may turn out to be more convenient than assembling it from separately purchased disks: a ready-made array is initially equipped with everything you need and requires only minimal configuration. The main thing is to clarify before buying which RAID levels the selected model supports.NAND flash memory
The amount of NAND solid-state memory installed in the SSHD (see "Drive Type").
Such memory acts as a high-speed buffer between the system and the hard drive itself. Usually, the most frequently called data is stored in it, which speeds up subsequent access to them; and when writing data to a disk, this data is first stored in a buffer before being transferred to disk platters. Most modern SSHD drives carry 8 GB of solid-state memory on board — this is considered the most reasonable compromise between speed and overall cost of the device.
Record technology
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CMR(Conventional Magnetic Recording) is a classic method of magnetic recording, characterized by high data access speed. CMR hard drives are used in systems where it is important to provide high (as far as possible) data read/write speed. These are user computers, security video surveillance systems, etc. The main disadvantage of CMR hard drives is the high complexity of creating volume drives, which is reflected in their price. Additionally, HDDs with CMR technology are quite “gluttonous” in terms of power supply.
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SMR(Shingled Magnetic Recording) — a promising technology for magnetic recording, which is called "tiled". SMR allows to achieve high data density, which in turn increases the capacity of memory drives and lowers their market value. SMR hard drives have slow rewriting speed, which makes such memory drives poorly suited for use in client computer systems. But they have proven themselves well when working as part of data processing centers, archives and similar systems for which low write / rewrite speed is not critical. However, some companies still produce SMR solutions for personal and even mobile systems. These HDDs use an optimized write/rewrite technology called Drive-Managed SMR (DM-SMR).
Data transfer rate
The speed of data transfer between the disk and client devices is determined by the type of drive, spindle speed, memory buffer size and connection connectors. The last parameter is the most important, since it is impossible to exceed the bandwidth of a particular interface.
Plates
The number of platters provided in the design of the hard drive.
Physically, a hard disk consists of one or more platters, on which information is recorded. Several plates can be provided in order to achieve the desired volume without increasing the form factor. At the same time, it is also necessary to install an appropriate number of reading heads in such a drive, which complicates the design, reduces its reliability, and increases the cost. Therefore, manufacturers choose the number of plates based on a reasonable compromise between these points, and for selection, this parameter is more of a reference than practically significant.
Operation power consumption
The amount of power consumed by the disk when reading and writing information. In fact, this is the peak power consumption, it is in these modes that the drive consumes the most energy.
HDD power consumption data is needed primarily to calculate the overall system power consumption and power supply requirements for the system. In addition, for laptops that are planned to be used often "in isolation from outlets", it is advisable to choose more economical drives.
Standby power consumption
The amount of power consumed by the disk "idle". In the on state, the disk platters rotate regardless of whether information is being written or read or not — maintaining this rotation takes the energy consumed while waiting.
The lower the power consumption while waiting, the more economical the disk is, the less energy it consumes. At the same time, we note that in fact this parameter is relevant mainly when choosing a drive for a laptop, when energy efficiency is crucial. For stationary PCs, “idle” power consumption does not play a special role, and when calculating the requirements for a power supply, it is necessary to take into account not this indicator, but the power consumption during operation (see above).
Reading noise level
The level of noise produced by the disk when reading and/or writing information. The source of sound in this case is the moving plates of the disk, as well as the mechanics that control the reading heads. The lower the noise level, the more comfortable the use of the device. The maximum noise produced by modern hard drives during operation is about 50 dB — this is comparable to the sound background in an average office.
Standby mode noise level
The amount of noise produced by a disk "idle", when no read and/or write operations are performed. The sound source in this case is the plates — they rotate all the time while the disk is on; since no other mechanics are involved, idle noise is generally lower than read/write noise. The lower the noise level, the more comfortable the use of the device. The maximum noise level of modern hard drives in standby mode is about 40 dB — this is comparable to quiet human speech.
