Single Ended and Differential SCSI Buses
The SCSI standard defines two electrical buses:
∙a single ended bus and
∙
Maximum Cable Length for SCSI Standards
Standard |
| Single ended |
| LVD |
| Maximum Number |
| |
|
|
|
|
|
|
| of Drives |
|
SCSI I |
| 6 m |
| 12 m | 7 |
| ||
Fast SCSI |
| 6 m |
| 12 m | 7 |
| ||
Fast Wide SCSI |
| 6 m |
| 12 m | 15 |
| ||
Ultra SCSI |
| 1.5 m |
| 12 m | 7 |
| ||
Ultra SCSI |
| 3 m |
| 12 m | 3 |
| ||
Wide Ultra SCSI |
|
|
| 12 m | 15 |
| ||
Wide Ultra SCSI |
| 1.5 m |
| 12 m | 7 |
| ||
Wide Ultra SCSI |
| 3 m |
| 12 m | 3 |
| ||
Ultra 2 SCSI |
|
|
| 25 m | 1 |
| ||
Ultra 2 SCSI |
|
|
| 12 m | 7 |
| ||
Wide Ultra 2 SCSI |
|
|
| 25 m | 1 |
| ||
Wide Ultra 2 SCSI |
|
|
| 12 m | 15 |
| ||
|
|
|
|
|
|
|
|
|
SCSI Bus Widths and Maximum Throughput
SCSI Standard |
| SCSI Bus Width |
| SCSI Throughput |
| |
SCSI I |
| 8 bits |
| 5 MB/s |
| |
Fast SCSI |
| 8 bits |
| 10 MB/s |
| |
Fast Wide SCSI |
| 16 bits |
| 20 MB/s |
| |
Ultra SCSI |
| 8 bits |
| 20 MB/s |
| |
Wide Ultra SCSI |
| 16 bits |
| 40 MB/s |
| |
Ultra 2 SCSI |
| 8 bits |
| 40 MB/s |
| |
Wide Ultra 2 SCSI |
| 16 bits |
| 80 MB/s |
| |
|
|
|
|
|
|
|
2ADAC Ultra2 S466 Hardware Guide