20
Adaptec SCSI Card 39160 User’s Reference
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 its SCSI ID (see Using SCSI Disk Utilities on page 24).
■Sync Transfer Rate—(Default: 160) Determines the maximum
synchronous data transfer rate that the SCSI card supports. We
recommend that you leave the maximum (default) value of 160
MBytes/sec.
■Initiate Wide Negotiation—(Default: Yes) When set to Ye s, 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: Ye s) When set to Yes, allows
the SCSI device to disconnect from the SCSI bus. Leave the set-
ting at Yes if two or more SCSI devices are connected to the
SCSI card. If only one SCSI device is connected, changing the
setting to No results in slightly better performance.
■Send Start Unit Command—(Default: Yes ) When set to Yes,
sends the Start Unit Command to the SCSI device at bootup.
The following three options have no effect if the SCSI Card BIOS is
disabled. (The SCSI Card BIOS is normally enabled by default.)
■Enable Write Back Cache—(Default: N/C) Can be used to
enable or disable the write-back cache on SCSI disk drives con-
nected to the host adapter. Leave this option at its default
setting of N/C (no change), which usually allows for optimum
drive performance.