SPEED

Another measure for hard disk performance is the rpm, which is the speed at which the disk platters spin. These come in 5400 rpm for Ultra DMA/33 and Ultra DMA/66, 7200 rpm usually for Ultra DMA/100, and 10,000 rpm for SCSI hard disks. The hard disks also have some onboard memory called the cache. The size of this cache also contributes to its performance. The bigger the better.

There are three types of hard discs - parallel ATA (PATA) and serial ATA (SATA). PATA is the oldest technology and is being slowly being replaced by SATA. Older motherboards that support only PATA natively can be made to support by using a SATA add-on card. However, most new motherboards natively support SATA. SATA supports data transfers up to a theoretical 300 MBps. SATA2 capable hard disks are manufactured by Samsun, Hitachi, Seagate, Western Digital, and Maxtor.