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.
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.
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.
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.
MTBF
Guaranteed (minimum) number of hard drive on-off cycles after which it will remain operational. The higher this number, the more reliable the drive.
