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SCSI Cable Length Guidelines
The number of drives and length of the cables used to connect the drives is a factor when
using SCSI-2, and Ultra SCSI drives. SCSI-2 and Ultra SCSI impose shorter cable
restrictions than SCSI-1. The total length of the SCSI cabling must not exceed the following:
Drives
SCSI-1
SCSI-2
Ultra SCSI
Wide Ultra2 (LVD) SCSI
1 to 4
6 meters
3 meters
3 meters
12 meters
5 to 7
6 meters
3 meters
1.5 meters
12 meters
8 to 15
N/A
N/A
N/A
12 meters
NOTE
The SCSI controller (on the system board or an adapter card) counts as one device.
The total length of the SCSI cabling is the sum of the following:
Ultra SCSI cable inside the system—14 inches (35.5 cm)
SCSI cable inside each device—average 8 inches (20 cm)
SCSI cable between the system and the first device
SCSI cable between each device
SCSI Cable Quality Guidelines
To ensure data integrity and optimum performance, do the following:
Use only Intergraph SCSI cables. Cables from other vendors may not provide adequate
shielding.
Use the shortest cables possible to connect SCSI devices to the system and to each other.
CAUTION
You should try to minimize cable flexing during handling. SCSI cables should not have any
creased bends. Take care when installing or replacing cables to insure that they do not
contact sharp metal surfaces or become excessively bent or twisted.
SCSI ID Guidelines
By default, specific devices use the following SCSI IDs:
System disk drive (standard) uses ID 0
SCSI bus always uses ID 7
4 mm DAT drive (optional) uses ID 6
NOTE
To easily determine the ID of each SCSI device on the system, restart the system. When the
BIOS screen displays, look for the list of SCSI devices and write down the ID for each device.
