Honestly if you got a 3600 X2 running at 2.8 Ghz you won't see a tangible difference, there WILL be a difference you can be sure of that, but not a tangible one. My advice would be buy an 8800GT if your graphics card isn't cutting it anymore, get 2GB of ram incase you already don't have it (which I doubt), and stay with this build until Nehalem chips can be found on early 2009, because by then you will not only see a true difference in speed, but also more cores.