2400Mhz on an AMD64 is roughly 4000+ you dont need to oc as much on an AMD to make large jumps n P-rating. for instance i only have my CPU overclocked 325Mhz that changed my 2800+ Barton to a 3600+. oh yeah and overclocking your GPU is nowhere worth what overclocking your CPU is not to mention the gpu is the more expensive part that is more prone to hotter running temps