ACPI CPUfreq vs. Intel P-State Scaling With Linux 3.15

With the Xonotic first person shooter running with low quality settings, ACPI CPUfreq with the performance scaling governor delivered the best performance while the Intel P-State driver with the powersave governor was running significantly slower. In three of the configurations the frame-rates were 260~270 FPS but Intel P-State with powersave was just 204 FPS while the ACPI cpufreq performance was up at 288 FPS.

While Intel P-State in the power-saving mode led to the slowest performance, it did consume the least amount of power during testing. To no surprise, ACPI CPUfreq with the performance scaling mode consumed the most amount of power.

ACPI CPUfreq with the performance scaling governor led to the best performance-per-Watt for this Intel Extreme Edition system.

Next I ran tests of the scaling configurations when upping Xonotic to ultimate image quality settings so that the graphics card would be more taxed rather than the CPU. In this configuration, the Intel P-State and ACPI CPUfreq drivers offered similar performance with the performance governors while the other scaling governors led to lower frame-rates.

The performance governors for both P-State and ACPI CPUfreq led to similar performance-per-Watt with this open-source game and its visual intensity being maxed out.