Serial attached SCSI (SAS) is the next generation bus technology designed for connecting hard disks, and other secondary storage devices like optical and tape devices to the computer system. SAS will replace the aging SCSI technology in server systems and high end storage for corporate and enterprise markets. SAS devices use serial links that operate at higher speeds and consume lower power than the SCSI busses. SAS currently in its current revision supports up to 3 Gb/s data transfers. SAS uses the existing SCSI protocol and commands over serial links. SAS is backwards compatible with SATA devices. Tagged Command Queuing (TCQ) technology, featured on some SAS products, allow for high performance SAS disks. SAS supports higher number of devices (disk) than SCSI busses without loss of performance. This allows for JBOS and RBODs with a greater number of disks. Since SAS is based on point to point and full duplex links, expanders can be used to connect multiple SAS devices to a single port. SAS devices support hot-plug capability and can be used with external JOBDs. SAS devices are generally well suited for business critical, reliable and highly available environments. Some SAS products can also be used in certain cluster configurations with a shared disk model. More information available at www.t10.org