SCSI Bus Width (bits)

SCSI Bus Speed (MB/s)

Specification

SCSI-1

8

5

Small Computer System Interface

Fast SCSI

8

10

Small Computer System Interface-2 (SCSI-2)

Fast Wide SCSI

16

20

SCSI-3 Parallel Interface (SPI)

Ultra SCSI

8

20

SCSI-3 Fast 20 Parallel Interface (Fast-20)

Wide Ultra SCSI

16

40

SCSI Parallel Interface-2 (SPI-2)

Ultra2 SCSI

8

40

SCSI Parallel Interface-2 (SPI-2)

Wide Ultra2 SCSI

16

80

SCSI Parallel Interface-2 (SPI-2)