In past months on Phoronix we have done many CPUfreq tests to see the impact of the different scaling governors and with Intel hardware how the CPUfreq driver compares to Intel P-State in terms of performance and power consumption. As we haven't done such ACPI CPUfreq tests on the AMD side in a long time, here's some benchmarks using a Kaveri APU and selecting the different scaling governors during performance benchmarking.
For this testing I took the AMD A10-7800 quad-core APU that was running on the Ubuntu 14.04 system with the Linux 3.16 stable kernel and Mesa 10.3-devel and ran a series of CPU/GPU benchmarks while changing out the CPUfreq scaling governor each time. The available governors tested for this article were ondemand, conservative, performance, and powersave.
Besides looking at how the raw performance was impacted by using the different scaling governors, the AC system power consumption was monitored and the performance-per-Watt also measured using the Phoronix Test Suite as was the CPU frequency states. This testing is very straight forward so let's get right to the results.