Computer Hardware
SCSI
Definition
Small Computer System Interface (SCSI) is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, electrical, optical and logical interfaces.
Why It Matters
SCSI was for a long time the dominant interface for high-performance hard drives, scanners, and other peripherals, especially in servers and workstations. It allowed for multiple devices to be connected in a "daisy chain".
Contextual Example
In the 1990s, a high-end server would use SCSI hard drives for their superior performance and reliability compared to the consumer-grade IDE drives of the era.
Common Misunderstandings
- SCSI as a parallel physical interface is now largely obsolete, replaced by SAS (Serial Attached SCSI) and iSCSI.
- However, the underlying SCSI command set is still widely used in modern storage protocols like SAS, iSCSI, and Fibre Channel.