aac scsi raid driver performance

[Ahnjoan Amous]

I can not say I understand why, but a CPU upgrade seems to have solved
my I/O problems.  If you read this thread you will see a fairly
consistent test of two concurrent sequential writes to different SCSI
devices on the same SCSI channel.  This test was to figure out why
GEOM mirror writes were so slow, and GEOM mirror tests were to figure
out why ggatec/ggated duplication was so slow.

I have re-installed my slower CPUs and see the poor IO performance
return so I am fairly confident that my conclusion can be supported by
testing.

FYI – Hardware
PowerEdge 2650, 2.4G/533/512L2/0L3, 1G ram, PERC 3/Di, 2x36G & 3x300G drives
I have two identical 2650s in this configuration for testing.

The CPU upgrade is a 3.066G/533/512L2/1ML3

For more detail in the difference…
Old CPU (slow concurrent IO) model number is SL6VL
New CPU (fast concurrent IO) model number is SL72G

Now on to e-bay to find a couple more of these!

Results: My IO speed almost tripled…  I'm able to get over 55MB/sec to
each drive in the concurrent write test on the new CPU, much better
than the 20MB/sec to each drive in the same test on the old CPU.

Thanks again for all the help.