Adaptec 29320A-R User Guide - Page 47

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 its SCSI ID (see Using SCSI Disk Utilities on page 3-16). s 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: s 320, 160, or 80-The BIOS negotiates at 80 MB/sec. s 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 (*). Negotiation Rate Narrow mode Wide mode Allowable Maximum Rates (MB/sec) *40.0, 33.3, 20.0, 16.6, 10.0, 5.0, ASYN *320, 160, 80.0, 66.6, 40.0, 33.3, 20.0, 10.0, ASYN Note: If Initiate Wide Negotiation is set to No, the rates for Wide devices are half those shown in the table. s 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. 3-6