newer MPT speed issue on Linux

newer MPT speed issue on Linux

[Roger Heflin]

Hello,

I am have tested with Sles9.1sp1, Sp3, and kernel.org 2.6.17.6 and
here are some results:
		
SLES9.1sp1 (kernel only)	100-120MB/second writes  75-80MB/second reads
SLES9.0sp3			20-30MB/second writes
2.6.17.6			20-30MB/second writes   140-150MB/second reads

This is with  the LSI Logic / Symbios Logic FC929X Fibre Channel Adapter 
(rev 81)

All 3 are with a SLES9sp3 distribution and are on the same machine with 
only the kernel
being changed.   The test is a simple "dd if=/dev/zero of=/dev/dk001/two 
bs=65536 &"
with vmstat being used to determine io speed.   Bonnie++ is getting 
similar results
to what dd is generating when writing to a filesystem.

The fiber channel card is hooked to a external raid5 chassis, and it 
being accessed
though LVM.

Are there some parameters that I am missing that could speed the writes up?

The reads on the newer driver are a nice improvement, but the writes on
the newer driver are horrible in my testing.

                               Roger