Adaptec GDTSETUP Bedienungsanleitung PDF herunterladen (Seite 94)

1. Sync. Transfer: Enable

The SCSI-bus allows an asynchronous and a synchronous transfer. Every SCSI device must

be able to perform the first type of transfer, the second one is optional. The advantage of

the synchronous transfer lies in a higher data transfer rate as the signal transfer times on

the possibly long SCSI-cable have no influence on the transfer rate anymore. Two SCSI-bus

participants wanting to exchange data between each other have to check if and how (i.e.,

with which parameters) a synchronous data transfer between them is possible. Therefore,

the mere setting does not automatically enable synchronous data transfer; this mode is

only effective if both devices support it and after they have checked their capability of

communicating with each other in this mode.

2. Sync. Transfer Rate

The maximum synchronous transfer rate can be limited. This limitation may become nec-

essary if a particular SCSI cabling does not allow the maximum rate the drive and the con-

troller could achieve. In our example, we leave the rate at 20.0 MB/s (for Wide SCSI at 20.0

MB/s, Wide/Ultra SCSI at 40.0 MB/s and Wide/Ultra2 SCSI at 80.0 MB/s).

Note: In order to select a transfer rate above 10.0 MB/s the Protocol has to be set to SCSI-

III.

3. Disconnect: Enable

The concept of the SCSI-bus allows several participants. All these participants should be

able to use the bus in a manner that causes the least reciprocal disturbance or obstruction.

A participant should therefore vacate the bus if he does not need it. For reasons of per-

formance, it is particularly important to guarantee a high degree of overlapping of the ac-

tions on the SCSI-bus. This high degree of overlapping can be achieved if a SCSI device is

allowed to disconnect, thus leaving the bus to be used by other participants. If there is only

one SCSI device connected to the SCSI-bus, Disconnect should be disabled.

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Adaptec GDTSETUP Bedienungsanleitung Seite 94