Features
The general purpose of a hard drive is the type of devices for which it was originally intended.
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For PC. Hard drives designed for use with conventional consumer computers and laptops. At the same time, the possibility of installing an internal HDD (see "Performance") directly depends on the form factor (see the relevant paragraph), while external models are not subject to such restrictions — it is enough for them to have the appropriate connection connector. Also note that almost all external hard drives are designed specifically for PCs; making server models external is not technically justified.
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For the server. Hard drives designed for servers have increased speed and reliability, because they constantly have to receive and give large amounts of information. To ensure speed, they may provide an increased rotation speed (up to 15,000 rpm). Such drives are made only internal (see "Performance"), and, in addition to SATA, they can use other, more specific connection methods — for example,
SAS(see "Connection interfaces").
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For game console. Specialized hard drives designed for use with game consoles. They are made only external (see "Performance"), they are intended mainly for storing games — including saves and user settings profiles. The main difference between such devices and classic external HDDs is
...precisely the optimization for working with game consoles, including the availability of special software tools for improved integration. Many of these drives are originally designed for a specific model or family of set-top boxes.Cache memory
The amount of internal hard drive memory. This memory is an intermediate link between the high-speed computer RAM and the relatively slow mechanics responsible for reading and writing information on disk platters. In particular, the buffer is used to store the most frequently requested data from the disk — thus, the access time to them is reduced.
Technically, the size of the buffer affects the speed of the hard drive — the larger the buffer, the faster the drive. However, this influence is rather insignificant, and at the level of human perception, a significant difference in performance is noticeable only when the buffer size of the two drives differs many times — for example,
8 MB and
64 MB.
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.
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).
Shockproof
A parameter that determines the resistance of the hard drive to drops and shocks during operation (that is, in the on state). Shock resistance is measured in G — units of overload, 1 G corresponds to the usual force of gravity. The higher the G number, the more resistant the disc is to various kinds of concussions and the less likely it is to be damaged, say, in the event of a fall. This setting is especially important for external drives and drives used in laptops.
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.
