Looks like teh reason for my poor RAID perfromance was because I had successfully striped one drive
Found one of the SATA connectors were not up to the job.
Now I am going through the motion of complete re-installing (great) and think this time round all should be a lot better and the performance I desire is just hours away (again I refer to the greatness of re-installing)
Well that does explain a lot, glad to hear you got to the bottom of this Mav, i did think your RAID performance was pretty poor even if it had a crazy stripe size etc or was being controller limited.