AMD created quite a buzz a short while before launch, by achieving a staggering clock speed of 8.429 ghz with the AMD FX8150 processor. This is going to be just a dream however, as the mainstream audience won’t be using liquid nitrogen or helium to cool their hardware.
Today we are using our long term favourite air cooler, the Noctua NH D14. This has won more awards worldwide than any other air cooler on the market. It may cost a small fortune, but no air cooler has yet to knock it from the performance throne.
We have a lot of experience with the Gigabyte 990FXA-UD7 motherboard and have always achieved great overclocked results with it. For this section of the review, we wanted to get the system stable to 4.6ghz so we could compare clock for clock against the Core i5 2500k and Core i7 2600k, on the next page.
The bios is really straightforward to use and due to the ‘no compromises’ design has fantastic power regulation and stability in an overclocked state.
We changed the hardware thermal control to disabled.
By adding another 0.100V we managed to get the system stable at 4.6ghz. As simple as that. It really is a testament to the quality of the Gigabyte 990FXA-UD7 that a 1 GHZ overclock is such a painfree process.
System validation at 4.6ghz is available here. As you can see, the system is perfectly validated at this speed, but it didn’t certify at the reference clock speeds of 3.6ghz. Bizarre.
We did manage to get the processor clocked even higher, but we will follow up shortly in the review, after testing against the Intel systems, on a clock per clock basis.
It is worth pointing out that the Gigabyte 990FXA-UD7 has no bios setting to disable APM (Application Power Management). Without this disabled, the motherboard will maintain the TDP limit when overclocking or overvolting above the limits. As a result APM will throttle some of the cores back to lower Pstates during heavy, multithreaded workloads reducing performance.
To get around this, we have to use AMD OverDrive software (above). We enable TurboCore, apply, then disable TurboCore … this in effect also disables Application Power Management.
Special thanks to Sami Makinen for lending us some of his expertise to work around this issue.