Features
The general purpose of a hard drive is the type of devices for which it was originally intended.
—
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.
—
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").
—
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.Record technology
—
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.
—
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).
RPM
For drives used in a PC (see "Intended use"),
5400 rpm(normal) and
7200 rpm(high) are considered standard speeds. There are also
more specific options, including models with the ability to adjust the speed depending on the load. In server HDDs, in turn, higher speeds can be used —
10,000 rpm and even
15,000 rpm.
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.
Average search time
The time it takes for the hard disk mechanics to find random requested data to read. For each specific case, the search time is different, as it depends on the location of the data on the surface of the disk and the position of the read head, therefore, the average value is indicated in the characteristics of hard drives. The lower the average seek time, the faster the disk works, all other things being equal.
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.
