User guide

support.dell.com Installing and Configuring SCSI Drivers 3-9
 Initiate Wide Negotiation
— Determines whether the host adapter attempts
16-bit data transfer instead of 8-bit data transfer. The default is
Ye s
.
NOTE: Some 8-bit SCSI devices may have trouble handling wide negotiation,
which may result in erratic behavior or a hang condition. For these devices, set
Initiate Wide Negotiation
to
No
.
When this option is set to
Ye s
, the host adapter attempts 16-bit data transfer.
When this option is set to
No
, 8-bit data transfer is used unless the SCSI device
itself requests wide negotiation. The effective transfer rate is doubled when
16-bit data transfer is used because the data path for wide SCSI is twice the size
of normal 8-bit SCSI.
 Enable Disconnection
(sometimes called disconnect/reconnect) — Determines
whether the host adapter allows the SCSI device to disconnect from the SCSI
bus. Enabling disconnection allows the host adapter to perform other operations
on the SCSI bus while the SCSI device is temporarily disconnected. The default
setting is
Ye s
.
Leave
Enable Disconnection
set to
Ye s
if two or more SCSI devices are con-
nected to the host adapter. This optimizes SCSI bus performance. If only one
SCSI device is connected to the host adapter, set
Enable Disconnection
to
No
to achieve slightly better performance.
 Send Start Unit Command
— Determines whether the start unit command is
sent to the SCSI device during the boot routine. The default is
Ye s
.
Setting this option to
Ye s
reduces the load on your computer's power supply by
allowing the host adapter to start SCSI devices one at a time when you boot your
computer. When this option is set to
No
, the devices are allowed to start at the
same time. Most devices require you to set a jumper before they can respond to
this command.
NOTE: For many devices, if
Send Start Unit Command
is set to
Ye s
, the boot
routine time will vary depending on how long it takes each drive to start.
 Enable Write Back Cache
— Signals the completion of a write request as soon
as the data is in cache. Actual writing to the disk occurs at a later time. The
default setting is
N/C
.
 BIOS Multiple LUN Support
— Provides support for peripherals that contain
multiple SCSI devices, such as autoloading tape drives and CD-ROM changers.
NOTE: The setting for
BIOS Multiple LUN Support
must be
Enabled
if a tape
autoloader is connected.
 Include in BIOS Scan
— Enables you to set whether the system BIOS scans
this device during system start-up. The default is
Ye s
.
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The advanced host adapter settings should not be changed unless absolutely neces-
sary. These values are set by Dell, and changing them may cause conflicts with the
SCSI devices.