6GBs SAS Interface Ready

The SCSI Trade Association (STA), a member-run industry association established to support and promote SCSI technology, announced today that the next generation of Serial Attached SCSI (SAS) is ready to enter the enterprise storage market after five years of research and development.

6Gb/s SAS is the marketing name for the new technology, in contrast to the name of the standard specification, SAS–2, designated by T10. The SAS–2 specification describes the features and capabilities for 6Gb/s SAS products and STA defines 6Gb/s SAS as a required set of features. The T10 Technical Committee is under the direction of the InterNational Committee for Information and Technology Standards (INCITS).

Harry Mason, Director of Industry Marketing, LSI, and President of STA commented: “This new generation of SAS provides investment protection by preserving existing SAS and Serial ATA (SATA) installations, while propelling the market ahead with important new capabilities. 6Gb/s SAS extends SAS architecture deeper into enterprise storage by doubling transfer rates, improving the scalability of the topology and increasing overall Reliability, Availability and Serviceability (RAS) attributes. These capabilities support the challenges of clustering, scale-out and storage tiering, including the growing interest in solid state drives (SSDs).”

John Lohmeyer, Chair of the T10 Technical Committee and Principle Engineer, LSI, stated: "During the five years since the first SAS standard was approved, the T10 committee did not slow down. SAS–1.1, which was published three years later, contains many significant enhancements, but did not increase the data transfer rate. SAS–2, which doubles the data rate to 6Gb/s, is now in the final approval phase. T10 has recently approved two follow-on projects to further enhance SAS."

The 6Gb/s SAS generation was designed to maintain backward compatibility with 3Gb/s SAS, as well as with 1.5Gb/s and 3Gb/s SATA, allowing these technologies to operate in the same system. As a result, SAS-based systems can support both SAS and SATA HDDs, providing a storage capability that operates seamlessly with greater speed and capacity than any storage system to date.

6Gb/s SAS Product Features Include:

• Throughput doubled from 3Gb/s to 6Gb/s.
• Standardized expander zoning for increased security.
• Expander self-discovery speeds up the device discovery process during power-up.
• Spread Spectrum Clocking (SSC) reduces electromagnetic interference.
• Mini-SAS cabling is required for external cabling (SFF-8088 and SFF-8087), easing cabling decisions.

Additional performance enhancements to 6Gb/s SAS which contribute to superior internal and external storage system configurations include wide ports, dual-port drives and full-duplex data transmission. Cables have lengthened to ten meters as opposed to six meters used for 3Gb/s SAS. 6Gb/s SAS protects investment in storage systems, as additions can be made as needed to the existing SAS system no matter the size or configuration. In addition, PCI Express, Gen. 2, has been increasingly associated with 6Gb/s SAS system configurations as the two technologies are highly compatible and complementary in building large, powerful storage systems.

The first plugfest to be devoted entirely to 6Gb/s SAS will be held the week of Nov. 10 at the University of New Hampshire IOLab facility.