Installing the A6828A Adapter

Specifying SCSI Parameters

Maximum Data Transfer Rate

The firmware suggested default for the A6828A adapter’s maximum data transfer rate is the adapter’s maximum speed (160 MB/s). The A6828A can communicate with all LVD or SE devices that have speeds up to 160 MB/s. This includes the following speeds (synchronous communication over a Wide bus):

 

•

Fast (20 MB/s)

 

•

Ultra (40 MB/s)

 

•

Ultra2 (80 MB/s)

 

•

Ultra160 (160 MB/s)

 

The actual transfer rate between the adapter and a SCSI device depends

 

on the transfer rate that was negotiated between the adapter and the

 

SCSI device. However, the actual rate will never be greater than the

 

maximum data transfer rate set for the adapter.

 

For example, if you set the A6828A’s maximum data transfer rate to

 

NOLIMIT (which is same as 160 MB/s, in this case), and then connect a

 

disk drive that has a maximum data transfer rate of Ultra2 (80 MB/s),

 

the actual transfer rate will be 80 MB/s.

 

HP recommends that you always set the A6828A’s maximum data

TIP

 

transfer rate to MAX or NOLIMIT (whichever is applicable to the system),

 

unless you are trying to debug a communication problem between the

 

adapter and a specific SCSI device. Using MAX or NOLIMIT allows the

 

adapter’s maximum transfer rate (160 MB/s) to be used.

 

 

 

You can set the A6828A’s maximum data transfer rate in two ways, as shown in Table 2-2 on page 22.

To set the maximum data transfer rate for A6828A HBA installed in PA-RISC based system, see “Setting Maximum Data Transfer Rate for A6828A Host Bus Adapter Installed in PA-RISC Based System” on page 28.

To set the maximum data transfer rate for A6828A HBA installed in Itanium®-based system, see “Setting Maximum Data Transfer Rate for A6828A Host Bus Adapter Installed in Itanium‚-Based System” on page 32.

Chapter 2

27