Adaptec AHA-2740W User Manual page 69

overhead. In multidevice environments, disconnect should normally
be enabled to take advantage of the disconnect/reconnect feature.
If a particular SCSI device does not support disconnect/reconnect,
then Enable Disconnection should be disabled (set to no). If a
particular SCSI device does support disconnect/reconnect, then
Enable Disconnection should be enabled (set to yes). Most SCSI
devices today do support disconnect/reconnect.
Initiate Sync Negotiation
This option determines whether or not the host adapter will initiate
synchronous negotiation with the SCSI device.
When set to yes, the host adapter will initiate synchronous negotia-
tion with the SCSI device. When set to no, the host adapter will not
initiate synchronous negotiation with the SCSI device. The host
adapter, however, will always respond to synchronous negotiation
initiated from the SCSI device. The default setting is yes.
If neither the host adapter nor the SCSI peripheral negotiate for
synchronous data transfers, all data transfers will be asynchronous.
Note:
Some older SCSI-1 devices may have trouble handling
synchronous negotiation, which may result in erratic behav-
ior or a hang condition. For these devices, set Initiate Sync
Negotiation to no.
Maximum Sync Xfer Rate
This option determines the maximum synchronous transfer rate
(MBytes/sec), that the host adapter will support. The host adapter
supports rates up to the Fast SCSI maximum of 10 MBytes/second.
The default value is 10.0 MBytes/sec. Valid values are 10.0, 8.0, 6.67,
5.7, 5.0, 4.4, 4.0, and 3.6 MBytes/sec
Note:
These values refer to 8-bit data transfers only. If 16-bit
data transfers are enabled, the effective rate is doubled.
The Fast SCSI synchronous data transfer rates are 10.0, 8.0, 6.67, and
5.7 MBytes/sec. If the host adapter is set not to negotiate for syn-
chronous data transfer (i.e., Initiate Sync Negotiation is set to no),
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AHA-2740W/2742W/2744W User's Guide
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Configuring the Host Adapter
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