Scsi Cable Length Guidelines; Scsi Cable Quality Guidelines - Intergraph InterServe 800 SL System Reference Manual

NOTE Most SCSI adapters do not recognize a hard disk drive that was formatted using a different
brand of adapter. For example, a hard disk drive formatted with an Adaptec SCSI adapter
will not work with a Symbios SCSI adapter. You must use only Symbios-formatted hard disk
drives with a Symbios SCSI adapter, the primary adapter included with the InterServe 800
SL.

SCSI Cable Length Guidelines

The number of drives and length of the cables used to connect the drives is a factor when
using SCSI-1, Fast SCSI (SCSI-2), Ultra SCSI, and Wide Ultra SCSI drives. Fast SCSI,
Ultra SCSI, and Wide Ultra SCSI impose shorter cable restrictions than SCSI-1. The total
length of the SCSI cabling must not exceed the following:
Drives
One to Four
Five to Seven
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:
u
Wide Ultra SCSI cable inside the system - 52 inches (132 cm)
u
Ultra SCSI cable inside the system - 14 inches (35.5 cm)
u
SCSI cable inside each device - typically 8 inches (20 cm)
u
SCSI cable between the system and the first device
u
SCSI cable between each device

SCSI Cable Quality Guidelines

To ensure data integrity and optimum performance, do the following:
u
Use only Intergraph Computer Systems SCSI cables. Cables from other vendors may
not provide adequate shielding.
u
Use the shortest cables possible to connect SCSI devices to the system and to each other.
SCSI-1 Fast SCSI-2
19.8 ft 9.9 ft
(6 meters) (3 meters)
9.9 ft 9.9 ft
(3 meters) (3 meters)
Ultra SCSI Wide Ultra SCSI
9.9 ft 9.9 ft
(3 meters) (3 meters)
4.5 ft 4.5 ft
(1.5 meters) (1.5 meters)
41