Ondemand vs. Performance CPU Governing For AMD FX CPUs On Linux 3.17

The one area where the CPUfreq performance vs. ondemand governor can make some impact is with the gaming tests where the GPU tends to be more taxed than the CPU. These differences also tend to be more noticeable when using the open-source graphics drivers rather than the closed-source AMD/NVIDIA blobs. For this testing, a Radeon HD 6870 graphics card was used with the mature R600 Gallium3D driver from Mesa 10.4 and using the Linux 3.17 kernel for the latest DRM support.

For the Xonotic game, the performance governor led to 26% faster performance than the default ondemand governor. (Just to point out, the FX-9590 tests from Monday and the prior tests this weekend included no such gaming tests.)

Using the CPUFreq performance governor led to an average reported CPU temperature 7 Celsius higher than the default ondemand governor and the peak temperature was 9 Celsius higher.

Using the performance governor also caused the overall system power usage to rise by about 14% and the peak power usage was higher by about 26%.

When testing Xonotic with ultra image quality settings, the performance governor was just faster by 21%.