Mark Randelhoff wrote:
[ ... ]
> The expected data rates are quite low. It would be a predominantly write 
> system at perhaps 3M bytes a second (lets say worst case 5M a second) 
> with the occasional requirement to read - perhaps 1M a second while the 
> writing continues. I am not presently using a PCI-X motherboard but it 
> is likely that we will move in that direction by the end of the year.

Please be aware that RAID-5 is best suited for read-only and read-mostly 
volumes.  RAID-5 is not well-suited for write-mostly volumes, although your 
expected transaction rates seem to be low enough that you ought to be OK.

RAID-10 might be a better choice.

-- 
-Chuck