Beg to differ pfunk, but CPU power does matter in AH. It's not as important as the overall video card itself, but it does make a difference.
Not to get into a pissing match, but frankly I have a hard time believing your frame rates never go below 60 with your setup.
It might not go below 60 when flying around, but I'm willing to bet in furballs and other high-traffic areas it's definitely below 60.
Of course, you also did not specify the resolution, color bits or anti-aliasing settings you use either.