Have you bumped your Hypertransport back to X4 and kicked your memory back to 667, With your bus speed at 217mhz your hypertransport is running at 1085/2170 and the memory is probably around 435/870 MHZ. I,ve run them at 2.7 but it took 1.4 voltage to get there and does start heating up. About 2.6-2.65 is the most stable with a 4600 because it takes so much voltage to get any higher.