SCSI-1 8-BIT 5MB/SEC

FAST SCSI 8-BIT 10MB/SEC(又稱為SCSI-2)
FAST WIDE SCSI 16-BIT 20MB/SEC

ULTRA SCSI 8-BIT 20MB/SEC(又稱為SCSI-20)
WIDE ULTRA SCSI 16-BIT 40MB/SEC

ULTRA2 SCSI 8-BIT 40MB/SEC(又稱為LVD)
WIDE ULTRA2 SCSI 16-BIT 80MB/SEC

WIDE ULTRA3 SCSI 16-BIT 160MB/SEC(又稱為ULTRA-160)
WIDE=16BIT BUS頻寬設計..
只要是WIDE規格.BUS傳輸速度>>就規格上來說會被加倍.