Adaptec 29320A-R Manual page 48

QAS—(Default:Yes) Quick Arbitration and Selection reduces
the overhead of control release on the SCSI bus from one device
to another. This improvement reduces command overhead and
maximizes bus utilization. When enabled, this option is
available if it is implemented in the device drivers. However,
this option is not supported by the BIOS.
Initiate Wide Negotiation—(Default: Yes) Enables the SCSI
controller to initiate Wide Negotiation with the SCSI target.
When set to Yes, the SCSI card attempts 16-bit data transfer
(wide negotiation). When set to No, the SCSI card uses 8-bit
data transfer unless the SCSI device requests wide negotiation.
Note: Set Initiate Wide Negotiation to No if you are using
an 8-bit SCSI device that hangs or exhibits other
performance problems with 16-bit data transfer rate
enabled.
Enable Disconnection—(Default: Yes) When set to Yes, Enable
Disconnection allows the SCSI device to disconnect from the
SCSI bus. When set to No, the SCSI device cannot disconnect
from the SCSI bus. Leave the setting at Yes if two or more SCSI
devices are connected to the SCSI card. When Enable
Disconnection is set to No, the SCSI device cannot disconnect
from the SCSI bus, packetized transfers cannot occur, and
transfer rates are set at Ultra160 levels.
Send Start Unit Command—(Default: Yes) When set to Yes,
sends the Start Unit Command to the SCSI device at bootup.
This reduces the load on a computer's power supply by
allowing the SCSI card to turn on SCSI devices one-by-one
when the computer boots; otherwise, all SCSI devices turn on at
the same time.
Note: Check the device documentation to make sure the
device supports the command. On most devices, you must
also change a switch or jumper setting on the device to
enable the device to respond to the command.
Configuring the Adaptec SCSI Card with SCSISelect
3-7