(I apologize for offline topics) Using Catalyst 10.12 and onwards, or any of Twl's drivers I had no issue with my CPU/RAM speed being limited [I am sure its not in anyways related to the later, with respect to drivers vs CPU/RAM]. Currently with single cards (previously with 5850 and now currently with 6950) I have had no issues with my setup. My RAM: 4GB 800Mhz with 4-4-4-12 timings My CPU: I use P2 state at 2200Mhz with 0.85 CPU(V), 0.9250 NB(V)..never had any issue even in running Dragon age + mods at 4xSSAA all high as much as I can, or with ME2 with 4xSSAA, or with Oblivion with 24xEDAA with OOO, or even crysis at 4xSSAA (dx9) with CCC level 5 mod. (Those were in 5850 card itself..lol) My gaming res is 1680x1050. Only two games, ever in my life I had to use p1 state at 2700 MHz with 0.9875 CPU(V), 1.0 NB(V). Metro and GTA 4. A.K.A never used full speed of my quad..ever.. I have tested OCing, but I never had the satisfaction when I overclocked everything..but had superb satisfaction of under-clocking my CPU with lowest CPU(V) my setup can use.