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Adaptec Ultra320 SCSI Cards User’s Guide
SCSI Device Configuration Options
SCSI Device Configuration options can be set individually for each
connected SCSI device.
Note:
To configure settings for a SCSI device, you must know
Using SCSI Disk Utilities on page 3-16
■
Sync Transfer Rate (MB/sec)
—(Default: see following table) The
BIOS may negotiate for a transfer rate between controller and
device of up to 80 MB/sec for Wide transfers and 40 MB/sec for
Narrow transfers. The 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 (*).
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.
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
U320 UG.book Page 6 Tuesday, September 23, 2003 1:47 PM
