Hard Drive performance has increased significantly in recent years while simultaneously decreasing in price. When purchasing a new hard drive there are
several factors, other than drive capacity to consider:
RPM: The rotational rate of the drive is one of the largest factors in Hard Drive performance because it decreases the rotational delay for accessing data.
Common drive RPMS are 4200, 5400, 7200, 10000 and 15000. The higher the drive RPM, the greater the hard drive performance when other specs are the same.
When power consumption must be kept to a minimum, 4200RPM laptop drives are used.
Interface: Common drive interfaces include SATA, SCSI (in all its variants) and IDE(in all its variants). In general, SCSI drives are typically used in
servers because of the better performance at handling simultaneous requests. SATA is the current standard desktop Hard Drive interface. IDE is an obsolete
parallel interface no longer used in newer computers.
Form Factor: Current hard drives come in sizes ranging from 3.5 inch to 1 inch. The measurment indicates the actual size of the rotating data platters.
New Technologies: SSDs (solid state disks) were introduced in the last few years to address the primary disadvantage of conventional hard disk drives: moving parts.
An SSD consists of a large capacity flash memory array that has a disk drive interface (SATA, SCSI) to attach to a computer. While significantly more expensive than a
conventional hard drive, an SSD drive offers increased performance, mechanical shock resistance and increased reliability.