Maximum Cable Lengths - Adaptec 29320A-R Manual

Adaptec Ultra320 SCSI Cards User's Guide

Maximum Cable Lengths

The total length of cabling (internal and external) on the SCSI bus
cannot exceed the maximum lengths listed in the following table.
The third column lists the maximum number of SCSI devices you
can connect to the SCSI card.
Maximum
Cable Length
25 m (82.0 ft)
12 m (39.4 ft)
3 m (9.8 ft)
3 m (9.8 ft)
3 m (9.8 ft)
1.5 m (4.9 ft)
1
Mixing Fast/Ultra devices with Ultra320/Ultra160 and Ultra2 SCSI devices causes
the entire SCSI bus to default to Ultra SCSI speeds and cable length requirements.
2
Ultra SCSI data transfer rates do not currently support more than seven devices
connected to the SCSI card due to cable lengths.
2-14
Data Transfer Rate
Ultra320 SCSI (320 MB/sec)
Ultra160 SCSI (160 MB/sec)
Ultra2 SCSI (80 MB/sec)
Ultra320 SCSI (320 MB/sec)
Ultra160 SCSI (160 MB/sec)
Ultra2 SCSI (80 MB/sec)
Fast Wide SCSI (20 MB/sec)
Fast SCSI (10 MB/sec)
Ultra SCSI (40 MB/sec for 16-bit,
20 MB/sec for 8-bit)
Ultra SCSI (40 MB/sec for 16-bit,
20 MB/sec for 8-bit)
Maximum Devices
Supported
1
5-7
1
15
15
7
4
2