This is your board click here and as far as I know you do not need to alter anything, RAID uses 2 identical hard drives together and I see no reason that installing RAID would make any difference at all, RAID has nothing to do with the speed of the drives, the motherboard will have correctly identified the drive.
I think either you got the wrong end of the stick or whoever told you this was blethering.
What he might have meant, and you perhaps picked up wrong is, if you have 2 identical SATA drives and set them up on RAID 0 which is called striping it means windows will treat the 2 drives as one large one but because you are two seperate cables it can get the info off the drives faster than off a single drive.
Disadvantage of RAID 0 is if either drive fails you lose everything as half the programs on one drive and the other half is on the other drive. But it is faster.