| Name | Specification | # of Devices | Bus Width | Bus Speed | MBps |
| Asynchronous SCSI |
SCSI-1 | 8 | 8 bits | 5 MHz | 4 MBps |
| Synchronous SCSI |
SCSI-1 | 8 | 8 bits | 5 MHz | 5 MBps |
| Wide SCSI |
SCSI-2 | 16 | 16 bits | 5 MHz | 10 MBps |
| Fast SCSI |
SCSI-2 | 8 | 8 bits | 10 MHz | 10 MBps |
| Fast/Wide SCSI |
SCSI-2 | 16 | 16 bits | 10 MHz | 20 MBps |
| Ultra SCSI |
SCSI-3 SPI |
8 | 8 bits | 20 MHz | 20 MBps |
| Ultra/Wide SCSI |
SCSI-3 SPI |
8 | 16 bits | 20 MHz | 40 MBps |
| Ultra2 SCSI |
SCSI-3 SPI-2 |
8 | 8 bits | 40 MHz | 40 MBps |
| Ultra2/Wide SCSI |
Fast-40 SPI-2 |
16 | 16 bits | 40 MHz | 80 MBps |
| Ultra3 SCSI |
Fast-80 SPI-3 |
16 | 16 bits | 40 MHz | 160 MBps |
| Ultra320 SCSI |
Fast-160 SPI-4 |
16 | 16 bits | 80 MHz |
320 MBps |