This might be old news, but I've been running three WD 1.5TB Blacks in RAID5 off the Intel controller for about 3 months now and haven't had any issues. I've been very happy with the performance. Running with a P6X58D, i7 930, 12GB of Corsair, intel 160gb etc. If you're just after mass storage and speed isn't a huge deal then I think the on-board controller is just fine.