Types of Hard Disks

SATA HDD V.S SAS HDD
Two new serial interfaces to disk drives are replacing two venerable parallel interfaces. The Advanced Technology Attachment (IDE/ATA) interface will be succeeded by Serial ATA (SATA), and the Small Computer System Interface (SCSI) will be replaced by Serial Attached SCSI (SAS). These new point-to-point technologies provide greater dedicated bandwidth and smaller connectors, and SAS technology supports both SAS and SATA disk drives. The one-two punch of the SAS/SATA value proposition is simple: SAS hard drives deliver the speed, reliability and scalability demanded in high-availability enterprise environments, while high-capacity SATA drives are ideal for bulk storage applications, combining low cost per GB and greater reliability and scalability than their parallel ATA ancestors. Complementary by design, SAS boasts the best performance/dollar while SATA offers maximum capacity/dollar.

	Logo	Internal Cable Connector	Form Factor	Single Disk Capacity	Speed	RPM	Memory cache
SATA HDD			3.5" or 2.5"	250GB	1.5G/s	7.2K rpm	16 MB
SATA II HDD			3.5" or 2.5"	1.5TB	3.0G/s	7.2K rpm	32 MB
SAS HDD			3.5" or 2.5"	300GB	3.0G/s	10K/15K rpm	16 MB