Serial Attached SCSI

SAS
Serial Attached SCSI
Four red cables lead into a wide black electrical connector
SAS connector
Width in bits1
No. of devices65,535
Speed
  • SAS-1: Full-duplex[1] 3 Gbit/s (2004)
  • SAS-2: Full-duplex 6 Gbit/s (2009)
  • SAS-3: Full-duplex 12 Gbit/s (2013)
  • SAS-4: Full-duplex 22.5 Gbit/s (2017)[2]
StyleSerial
Hotplugging interfaceYes

In computing, Serial Attached SCSI (SAS) is a point-to-point serial protocol that moves data to and from computer-storage devices such as hard disk drives, solid-state drives and tape drives. SAS replaces the older Parallel SCSI (Parallel Small Computer System Interface, usually pronounced "scuzzy" [3][4]) bus technology that first appeared in the mid-1980s. SAS, like its predecessor, uses the standard SCSI command set. SAS offers optional compatibility with Serial ATA (SATA), versions 2 and later. This allows the connection of SATA drives to most SAS backplanes or controllers. The reverse, connecting SAS drives to SATA backplanes, is not possible.[5]

The T10 technical committee of the International Committee for Information Technology Standards (INCITS) develops and maintains the SAS protocol; the SCSI Trade Association (SCSITA) promotes the technology.

  1. ^ "Differences between SAS and SATA".
  2. ^ "24G SAS Data Storage Specification Development Complete; SCSI Trade Association Spotlights Technology at 2017 Flash Memory Summit". SCSI Trade Association. 2017-08-07.
  3. ^ Thompson, Robert Bruce; Thompson, Barbara Fritchman (24 July 2003). PC Hardware in a Nutshell: A Desktop Quick Reference. "O'Reilly Media, Inc.". p. 422. ISBN 978-0-596-55234-3.
  4. ^ NCR Corporation (1990). Scsi: understanding the small computer system interface. University of Virginia: Prentice Hall. p. 5. ISBN 9780137968558.
  5. ^ "SAS and SATA: Unparalleled Compatibility". Retrieved 2024-05-20.