I dont consider replacing that phenom a good choice atm since its still a pretty decent processor although if you can sell it for a decent price you could get an i5 2500k + z68 motherboard + 6950 for about 500$. The 2500k easily oc's to 4.5ghz with a cheap cooler for example a Cooler Master H212+ for about 30$. That rig would likely max any of those games. And dont forget most 6950 can be mod into 6970 unlocking extra shaders.