Dell Adaptec U320 SCSI Raid 0 or 1 Controller Card - Manual (Page 9)

4. Secure the controller with the system's retaining bracket.
5. Attach the activity light cable to the activity light connector on the Adaptec U320 SCSI RAID 0 or 1 controller and the
motherboard if needed. Make sure that pin 1 on the connector is aligned with pin 1 of the cable.
Configuring SCSI Drives
There are several things you may need to do to your SCSI hard drives and devices before you connect them to the Adaptec
U320 SCSI RAID 0 or 1:
Check the SCSI IDs
Set the termination
Connect the power cables
Since setup can vary from device to device, always refer to the device's documentation for specific instructions.
NOTE: If you connect Wide Ultra/Ultra SCSI devices to the same SCSI channel as Ultra320/160 and Ultra2 SCSI
devices, the data transfer rate for the Ultra320/160 and Ultra2 SCSI devices will drop to Ultra SCSI performance levels.
To achieve maximum data transfer rates for the newer SCSI devices, be sure to connect them on their own SCSI
channel.
The following are some guidelines for setting SCSI IDs and termination on your devices.
SCSI IDs
The Adaptec U320 SCSI RAID 0 or 1 and each device you connect to it must have a unique SCSI ID number ranging from 0
to 15 on each channel. No two devices on the same SCSI channel can have the same SCSI ID.