Overclocking
Overclocking
The fun news about the FX series processors is that they will all come unlocked. That means the CPU multiplier is unlocked allowing you to easily gain a little extra performance.
Overclocking wise you could use AMD OverDrive, but a true guru does his magic in the BIOS. With the new Turbo states you could alter the Max core but for ease of use we simply disable the Turbo mode altogether as we want a constant overclock on all eight cores.
We got the processor running up to 4600 MHz on all eight cores with a 35 USD OCZ Vendetta cooler + an additional fan blowing over the motherboard cooling down the VRM zone.
Some generic overclocking guidelines in the BIOS:
- Disable Turbo mode
- Disable APM Master
- Disable thermal states
- Set CPU voltage anywhere from 1.4V to 1.55V (make sure you have enough cooling!)
- Set DDR memory voltage 0.10V higher for increased stability. E.g. 1.55V would be 1.65V
- Increase the base multiplier
Again, make sure you have cooled your CPU and motherboard well. Don't skimp on cheap thermal paste.
We now incrementally increase the CPU base multiplier and end up at a bus speed of 200 x 23 multiplier - 4600 MHz. To achieve this we needed 1.44 Volts on the processor.
At this voltage level in combo with eight cores, the cheapo CPU cooler was borderline enough as temps increased to 80~90 Degrees C under massive multi-threaded CPU stress (Prime95).
If, during this overclock, your system shuts down, that's a new protection from AMD. You've reached either the heat, TDP or OCP limit (this seems to happen once the CPU pulls more than 26.5A from the 12V CPU rails (8pin and 4pin connectors). If that happens decrease the voltage a bit.
On the ASUS board tested today, when using the High setting for load line calibration the board should not reach the current protection limit that easily. Our end result on air thus is 4600 MHz on all eight cores. On proper liquid cooling 5 GHz should be a viable target as well.
The power draw however is intense as at this stage we consume roughly 430 Watts by stressing all eight CPU cores.
