Something more important to pay attention to would be the motherboard's Southbridge - X58 utilizes the ever-familiar ICH10R, which for all intents and purposes for RAID 0/1/10/0+1 is pretty good at doing simple RAID functionality like that.
As for RAID5, well, for hardware-assisted software RAID, your mileage may vary.
Use a small stripe size for OS raid volume,
since OS drives tend to random access little files all over the place
rather than do sequential reads of big files.
At first I had my OS drive at 256kb stripe (the default setting)
but it was even slower than a single drive.
After I recreated the array with 16kb stripe (the smallest setting)
my speeds increased dramatically.