I forgot the exact numbers, but FX5600 is basically a G80 board (your good old 6800 or 7800 Ultra), so for the most part, it will be faster - probably by 20% or so. Another thing to remember is that that card has a whopping 1.5 gig of ram on it, so you can run really high resolution screens on them without too much trouble. If you do 3D modeling or texturing, then yes, you would need something like that. For just regular gaming or what not, 8800GT should be enough, unless you need top class performance. Then again, if that's the case, you would've already build a Windows box for that