At 09:24 -0400 2/10/07, Ross S. W. Walker wrote: >Actually the real-real fix was to use the 'deadline' or 'noop' scheduler >with this card as the default 'cfq' scheduler was designed to work with >a single drive and not a multiple drive RAID, so it acts as a govenor on >the amount of IO that a single process can send to the device and when >you do multiple overlapping IOs performance decreases instead of >increases. Ah - that wasn't actually a complete fix Ross, but it did give a noticeable improvement in certain situations. I'm still chasing a real real 'general purpose' fix. S.