Author: Susan Bobholz, Market Development Manager
Serial Attached SCSI (SAS) is the logical evolution of the traditional parallel SCSI interface, and it represents the continuation of more than 25 years of technology development and infrastructure investment. In SAS, the SCSI protocol is transported over a serial interface. Compared to the existing parallel SCSI interface, SAS enables faster device interconnect speeds, simpler cabling and improved system reliability, while preserving existing SCSI capabilities. SAS also improves connectivity to larger numbers of drives and also enables compatibility with Serial ATA (SATA) drives. The SAS interface standard was developed by the T10 Technical Committee of the International Committee for Information Technology Standards (INCITS). The latest specification "Serial Attached SCSI version 1.1" has been adopted by the American National Standards Institute (ANSI). A wide variety of SAS products has been shipping for several years including hard drives, controllers, servers and networked storage systems.
What is SAS?
SAS is the high-speed serial successor to Ultra320 SCSI as well as an I/O infrastructure that provides for a wide range of storage solutions. SAS goes beyond a mere disk drive interface; it provides a set of components that include connectors, cables, and expanders that can be used to deploy a large number of solutions into the storage and server market. While SAS preserves the traditional SCSI usage model, it widens the types of applications and markets it can serve including blade storage, tiered storage and near-line storage, and shared storage between hosts.