D
D
X
X
P
P
S
S
/
/
D
D
X
X
P
P
S
S
P
P
l
l
u
u
s
s
/
/
D
D
X
X
P
P
S
S
-
-
U
U
/
/
D
D
X
X
P
P
S
S
P
P
l
l
u
u
s
s
-
-
U
U
O
O
n
n
l
l
i
i
n
n
e
e
M
M
a
a
n
n
u
u
a
a
l
l
114
When set to
Yes
, the SCSI device may disconnect from the SCSI bus. The SCSI device, however, may choose not to disconnect,
even if permitted by the SCSI controller. When set to
No
, the SCSI device is not allowed to disconnect from the SCSI bus. The
default setting is
Yes
.
Keep this item set to
Yes
if two or more SCSI devices are connected to the SCSI controller. This can optimize SCSI bus
performance. If only one SCSI device is connected to the SCSI controller, set this item to No to achieve better system
performance.
Send Start Unit Command
This option determines whether the Start Unit Command (SCSI command 1B) is sent to the SCSI device (most devices do not
require this). Enabling this item reduces the load on the system power supply by allowing the SCSI controller to power up SCSI
devices one at a time upon booting. Otherwise, all the devices power up at the same time. Most devices require you to set a
jumper before they can respond to this command.
When set to
Yes
, the Start Unit Command is sent to the SCSI device at system boot. When set to
No
, each SCSI device powers
up in the normal procedure.
The Send Start Unit Command setting is valid only if
the host adapter BIOS is enabled.
If this option is enabled for more than one SCSI device, the Start Unit Command is sent first to the device with the lowest SCSI
ID. When this device responds to the SCSI controller, the Start Unit Command is sent to the next highest SCSI ID with a setting
of Yes. The process continues until all supported devices respond to the SCSI controller.
If many drives are set to
Yes
for Send Start Unit Command, the boot time varies depending on how long it takes each drive to
spin up.
