Overclocking - Hitting The Limit At 2.70 GHz
We attempted to increase the CPU's frequency from 2.60 GHz to 2.70 GHz while retaining the default core voltage of 1.250 V. Since the Phenom lets you choose half multiplier steps, we tried raising the clock speed by 100 MHz using the 13.5x multiplier, but the system instantly became unstable. Therefore, we increased the core voltage step by step until the CPU became stable once more. Only after we had reached a core voltage of 1.400 V (+ 0.150 V) could we convince the system to complete the Prime 95 torture test without incident. Overclocking any further to 2.80 GHz proved completely impossible, despite further voltage increases.
The back of our Phenom 9600 Black Edition.
In our opinion, 1.400 V is too high for everyday operation for a 65 nm Phenom, as it carries too much risk of damaging the CPU.
It is obvious that we should not expect any high-frequency models as long as the Phenom uses the B2 stepping. On the other hand, there are B2-Phenoms that are able to reach 3.00 GHz, as we saw at the Phenom launch event - there is no rule by which you can determine a CPU's potential. Overclocking the Phenom processor is a matter of luck, and by no means as sure a bet as it is with the Core 2 processors of AMD's rival Intel.
