Adaptec SATA AND SCSI RAID CONTROLLERS User Manual
Page 76
A-14
Adaptec RAID Configuration Utility (ARC)
SCSI Device Configuration Options
The SCSI device settings allow you to configure certain parameters
for each device on the SCSI channel. To configure settings for a
specific device, you must know the SCSI ID assigned to that device.
If you are not sure of the SCSI ID, see
.
To access the SCSI Device Configuration options, select SCSI
Configuration
, then select Additional Options. The SCSI Device
Configuration options are described in the table below.
Note:
For maximum performance, Adaptec recommends that
you retain the default settings.
SCSI Device Configuration Options
Option
Default
Description
Maximum
Transfer Rate
N/A
Determines the maximum data transfer rate
that the SCSI channel supports. The maximum
effective data transfer rate is doubled when
is set to Yes and 16-bit
devices are attached. (
has no effect with 8-bit devices.)
Enable
Disconnection
Yes
Determines whether the SCSI channel allows
the SCSI device to disconnect from the SCSI
channel (sometimes called Disconnect/
Reconnect or Reselection).
Initiate Wide
Negotiation
Yes
Determines whether the SCSI channel attempts
16-bit data transfer instead of 8-bit data transfer.
The effective data transfer rate is doubled when
16-bit data transfer is used.
QAS
No
1
1. Adaptec recommends that you not enable QAS if you are using an enclosure that
contains Ultra320 expander ICs.
Determines whether QAS (Quick Arbitration
and Selection) is used to eliminate overhead
and speed up data transfers on the SCSI bus.
Packetized
Yes
Determines whether SCSI packetization
(encapsulation) is used to reduce overhead and
speed data transfer. The packetized SCSI
protocol provides a method for transferring
command and status information at the
maximum rate.