It's only SATA II? It must've been the C300 (my other option) that was SATA III.
How poor are Marvell's drivers compared to Intel's? Moving the drive involves taking out my video card and moving my stuff around because the cable is connected in a very inconvenient place, but if it's worth the change then I will gladly do it.
I changed the controller and it is now significantly faster.
I greatly appreciate all your help so far