Serial Attach SCSI (SAS)

As with Serial ATA, Serial Attached SCSI (SAS) is the logical evolution of SCSI, retaining SCSI's long-established software advantage. In addition, the Serial ATA (SATA) electrical and physical connection interface, which has much smaller connectors and cables, benefits SAS with greater system cooling and lower system cost. With enterprise storage requirements escalating and becoming more complex, factors such as larger capacity, greater density, security, scalability and accessibility are more critical than ever. Enterprise data centres must be online all the time, fulfil requests from numerous users simultaneously, allow for constant growth and expansion and be maintained during operation. SAS meets all of these demands while providing the highest performance. Aligning SAS and SATA technologies to serve storage users who need large capacities at a lower cost provides greater choice to the industry. 

3Gb/s SAS

SAS was launched at 3Gb/s and designed to replaces parallel SCSI which, much like Parallel ATA, could no longer keep pace with industry performance and scalability demands. SAS fulfilled the storage industry's need for faster systems with more advanced capabilities. SAS features which support faster performance include dual-port drives and wide ports, enabling full-duplex data transmission plus aggregated bandwidth. Universal connectivity is an added SAS advantage. 

Other advantages of SAS was its ability to interact with SATA technology and allowed both SAS and SATA drives to be run from a common SAS backplane, something that was never a possibility with older parallel SCSI and PATA technology. However it is important to note that SATA HDD will run on both SATA and SAS backplanes while SAS will only run on a SAS backplane and not SATA.

6Gb/s SAS

6Gb/s SAS has many enhancements beyond 3Gb/s SAS. It has more bandwidth per connection, greater scalability, and enhanced features. 3Gb/s SAS usage models will be preserved in 6Gb/s SAS along with the retention of 1.5 Gb/s and 3Gb/s SAS/SATA compatibility. There are many other targeted improvements beyond first generation 3Gb/s SAS, assuring enterprise storage users that SAS technology will continue to meet their needs.

6Gb/s SAS has just been released to the market and we expect to see this dominate the SAS market until the release of 12Gb/s SAS which is planned to be seen around 2012.