Dell Adaptec U320 SCSI Raid 0 or 1 Controller Card - Manual (Page 20)

BIOS can use this setting to set the starting point for negotiating the synchronous data transfer rate to a slower
speed. For example, in the case of Wide transfers, if the Sync Transfer Rate is set to:
320, 160, or 80—The BIOS negotiates at 80 MB/sec.
40 or lower—The BIOS negotiates at the Sync Transfer Rate setting.
Eventually, the BIOS completes negotiation. Later, the device driver takes over. The device driver uses this setting as a
starting point for negotiating data transfers.
The following table describes the maximum synchronous transfer rates. The default settings are designated by an
asterisk (*).
Negotiation Rate Allowable Maximum Rates (MB/sec)
Narrow mode *40.0, 33.3, 20.0, 16.6, 10.0, 5.0, ASYN
Wide mode *320, 160, 80.0, 66.6, 40.0, 33.3, 20.0, 10.0, ASYN
NOTE: If Initiate Wide Negotiation is set to No, the rates for Wide devices are half those shown in the table.
Packetized—(Default:Yes) Packetized protocol is required to operate at 320 MB/sec. When enabled, this option
is available if it is implemented in the device drivers. However, this option is not supported by the BIOS.
QAS—(Default:No) 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 system's power supply by allowing the SCSI card to turn on SCSI
devices one-by-one when the system 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.
The following options have no effect if the SCSI card BIOS is disabled. (The SCSI card BIOS is normally enabled by
default.)
BIOS Multiple LUN Support—(Default: No) Leave this setting at No if the device does not have multiple
LUNs. When set to Yes, the SCSI card BIOS provides boot support for a SCSI device with multiple LUNs (for
example, a CD jukebox device in which multiple CDs can be accessed simultaneously).
Include in BIOS Scan—(Default: Yes) When set to Yes, the SCSI card BIOS controls the SCSI device if it is
an INT 13 device (such as a SCSI disk drive) without device driver software. When set to No, the SCSI card