| Bus Width |
SCSI
Standard |
Maximum
Speed |
Maximum
Length |
Common Connectors |
8-bit
(Narrow) |
SCSI-1 |
5 MB/s |
6m
(19.6 ft.) |
Ribbon
IDC 50
Internal 50-pin connector for hard drives, CD drives,
etc.Centronics 50
Popular 50-contact connector for external peripherals
such as scanners and tape drives.
DB25
External 25-pin connector used by Zip drives, scanners,
and many Mac devices.
DB50
External 50-pin connector used by Sun
workstations.
|
SCSI-2
Fast SCSI,
Fast-10 |
10 MB/s |
3m
(9.8 ft.) |
Ribbon
IDC 50
Internal 50-pin connector for hard drives, CD drives,
etc.Half Pitch DB50
External 50-pin host and peripheral connector used by
Jaz drives and many CD drives. |
Ultra SCSI,
Fast-20 |
20 MB/s |
1.5m
(4.9 ft.) |
| Ultra2 SCSI |
40 MB/s |
12m
(39 ft.) |
16-bit
(Wide) |
SCSI-2,
Fast Wide
SCSI,
Fast-10 |
20 MB/s |
1.5m
(4.9 ft.) |
Half
Pitch DB68
Internal and external 68-pin connector used by most new
hard drives. The external version includes thumbscrews or latches. |
Ultra Wide
SCSI,
Fast-20 |
40 MB/s |
1.5m
(4.9 ft.) |
SCSI-3,
Ultra2 Wide (U2W) SCSI,
Ultra2 LVD SCSI,
Fast-40 |
80 MB/s |
12m
(39 ft.) |
Half Pitch DB68
Low Voltage Differential (LVD) cables and accessories
are required to achieve peak performance with U2W drives.
Very High Density Centronics 68
68-pin contact connector used on many servers &
RAID controllers.
SCA 80
80-contact connector used by SCA drives for RAID controllers |
Ultra3 SCSI,
Ultra160/m |
160 MB/s |
12m
(39 ft.) |
|
