Glossary of terms for Hard Drives
Type
The hard disks can be internal, external, for notebooks or servers. Internal hard disks are found inside the computer and the external hard drives are located outside the computer, being connected as an external unit. The internal hard disk can be used both for laptops and servers.
Capacity
The capacity represents the data amount which can be stored on the hard disk and is measured in GB.
Spindle Speed
Spindle speed is the speed at which the hard disk's platter spins and indicates the maximum number of revolutions per minute (RPM). This has the following values: 5400, 7200, 10000 or 15000 and a higher spin rate means that the data can be read much faster from the disk for a single operation.
Buffer Size
Buffer Size is the memory of the hard drive that is used to temporarily hold data, while it is being moved from one place to another. This is a very important aspect for the hard drive's speed and quality, and the bigger, the better.
Seek Time
Seek Time represents the time the hard disk's head needs to move, so that it can write or read information from a specific place.
Interface
The Interface represent the type of connection used by your hard drive to be connected to a computer. It can be: IDE (Integrated Drive Electronics), SATA (Serial ATA), SCSI (Small Computer System Interface), SAS (Serial Attached SCSI), USB (Universal Serial Bus) 2.0 or Firewire.
Transfer Rate
Transfer Rate is the speed at which a hard drive can transfer data and is highly dependent on the interface type used. For example, USB 2.0 has 60 MB/s transfer rate, ATA 133 has 133 MB/s, SATA has 150 MB/s, SATA II has 300 MB/s, Firewire 400 has 50 MB/s and Firewire 800 has 100 MB/s.
Form Factor
It represents the physical size of the hard disk and there are two models which are more popular: 2.5 inches, this being the proper size for a notebook and 3.5 inches, the particular size for a desktop system.