Dell Adaptec U320 SCSI Raid 0 or 1 Controller Card - Manual (Page 10)

The Adaptec U320 SCSI RAID 0 or 1 is preset to ID 7 for each channel and should not be changed. If you boot from a SCSI
hard disk, make sure the hard disk SCSI ID is set to 0. (Most SCSI hard disks are preset to SCSI ID 0 at the factory.) The
SCSI IDs for internal devices are usually set with jumpers; SCSI IDs for external devices are usually set with a switch on the
back of the device.
SCSI Termination
Proper termination of channels used with SCSI devices is critical in having the system work properly. The basics of
termination are:
Use SCSI cables certified for Ultra320 operation to allow the system to work at full speed.
NOTE: The cable provided with the Adaptec U320 SCSI RAID 0 or 1 has a built-in multi-mode terminator on one end.
This is meant to be located at the opposite end of the cable from the attachment to the controller. None of the drives
attached to this cable should be terminated.
Enable termination of the devices on each physical end of a SCSI cable (see note above). Use multi-mode terminated
cables only with termination on that channel disabled.
When using multiple SCSI channels on a single controller, as is possible on the Adaptec U320 SCSI RAID 0 or 1,
terminate each channel separately.
SCSI termination for Adaptec U320 SCSI RAID 0 or 1 is configured through the BIOS configuration utility. The controller has
two possible termination settings, as shown:
Setting Function
Auto (Default) Used for most cabling conditions
Disabled
Disabled controller termination unconditionally
The following figures show various SCSI cabling examples:
SCSI Cables
Dell recommends using Ultra320 SCSI drives and LVD SCSI cables designed and rated for Ultra320 use. These can be
purchased from Dell at www.dell.com . Using cables not rated for U320 operation may adversely impact the performance of
the system.
Installing Hard Drives
The Adaptec U320 SCSI RAID 0 or 1 Controller supports up to 4 drives. For optimal performance, install identical drives of the
same model and capacity. The drives' matched performance allows the array to function at the highest performance level.
While the Adaptec U320 SCSI RAID 0 or 1 is designed to work with Ultra320 and Ultra160 SCSI hard disk drives, it will
operate, at a reduced level of performance, with all legacy Ultra2, Ultra, and Single-Ended (SE) SCSI devices. Use of High