Adaptec 39106 manual Maximum Cable Lengths, Cable Length Data Transfer Rate

Adaptec SCSI Card 39160 User’s Reference

The following example shows LVD (Ultra160 and Ultra2) SCSI devices on Channel B and non-LVD SCSI devices on Channel A.

Built-in	Ultra160 and Ultra2	Non-LVD
terminator	SCSI devices	SCSI devices

T

T

T

T

Terminated

deviceTerminated devices

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		Maximum Devices
Cable Length	Data Transfer Rate	Supported
25 m (82.0 ft)	Ultra160 SCSI (160 MBytes/sec)	1
	and Ultra2 SCSI (80 MBytes/sec)
12 m (39.4 ft)	Ultra160 SCSI (160 MBytes/sec)1	15
	and Ultra2 SCSI (80 MBytes/sec)
3 m (9.8 ft)	Fast Wide SCSI (20 MBytes/sec)	15
3 m (9.8 ft)	Fast SCSI (10 MBytes/sec)	7
3 m (9.8 ft)	Ultra SCSI (40 MBytes/sec for 16-	4
	bit, 20 MBytes/sec for 8-bit)
1.5 m (4.9 ft)	Ultra SCSI (40 MBytes/sec for	5-72
	16-bit, 20 MBytes/sec for 8-bit)

1Mixing Fast/Ultra devices with Ultra160 and Ultra2 SCSI devices causes the entire SCSI bus to default to Ultra SCSI speeds and cable length requirements.

2Ultra SCSI data transfer rates do not currently support more than seven devices connected to the SCSI card.

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