Overclocking and Performance

I would like to say right away that Asus mainboards’ specifics that do not let us overclock Intel CPUs well and at the same time maintain all processor power-saving technologies, are not the case with AMD processors. You can lower the processor Vcore, increase it or leave at nominal and the CPU will work as instructed under load.

However, as soon as the load disappears AMD Cool’n’Quiet technology will kick in and the CPU will lower its frequency and core voltage.

Overall, I have been very please with AMD Phenom II X4 810 overclocking experience on Asus M4A78T-E. Overclocking hasn’t been so simple, clear, quick and easy for a while. Just raise the clock generator frequency and increase the processor Vcore if system loses stability monitoring the temperature at the same time. And then increase the frequency again. The only other thing you should keep an eye on is that the frequency of the North Bridge integrated into the CPU and the HyperTransport bus connecting the processor with the chipset North Bridge were close to the nominal 2000MHz. Taking into account the potential of Asus M4A78T-E mainboard, all these requirements are really easy to meet. For example, if I am ever invited to my kids’ school for an overclocking lesson, I will take something close to my current testbed configuration rather than an LGA775 or LGA1366 platform, which have much more things to take into account.

Our AMD Phenom II X4 810 processor at 230MHz frequency passed preliminary stability tests in LinX utility on Asus M4A78T-E mainboard without changing its Vcore from the nominal 1.3V. For your reference, the same processor managed to pass the same tests on Gigabyte GA-MA790XT-UD4P mainboard at 250MHz. Quite a difference, isn’t it? However, I didn’t know about it at that time. Besides, AMD processors do not require nominal Vcore settings to be in place for processor power-saving Cool’n’Quiet technology to work. Therefore, we continued our experiments. The end result turned out pretty good: we managed to overclock our CPU to 285MHz base frequency, i.e. 3.7GHz clock speed. Besides LinX utility, we tested the system stability with more than an hour run of Prime95 in Blend mode.

To increase the system performance we raised the frequency of the North Bridge integrated into the CPU to 2565MHz. that in its turn required raising CPU/NB Voltage to 1.275V. The processor core voltage had to be increased to 1.575V, but in idle mode it would drop together with the frequency multiplier.

By the way, when we used the integrated graphics core we had to stop at 275MHz frequency, because further increase led to evident system instability and serious image quality artifacts. It seems that maximum overclocking of a system using integrated graphics will seriously depend on the current memory frequency and timings and on the integrated graphics core settings in the mainboard BIOS.