Geoff over at TR pits the two SATA RAID controllers from Intel & NVIDIA against each other in an all-out death match. I've personally had funky experiences with both controllers, & prefer to use Silicon Image's stuff when I can.

"We've spent a couple of months running Intel's ICH7R and NVIDIA's nForce4 Serial ATA RAID controllers through our exhaustive suite of storage tests, and the results are something to behold. We started with a single drive and worked our way up through RAID levels 0, 1, 10, 0+1, and 5 with two, three, and even four hard drives."