An Early Look At The AMD P-State CPPC Driver Performance vs. ACPI CPUFreq

HITMAN 2 running via Steam Play was also seeing lower performance but not as bad with schedutil and ondemand for amd-pstate.

At least for this high-end Zen 3 desktop system, the amd-pstate performance when using ondemand/schedutil tended to perform much more poorly than using acpi-cpufreq. With the "performance" governor tending to keep the CPU at its top performance state, there wasn't much difference between the two drivers.

The Unvanquished open-source game was seeing some of the most severe regressions when using amd-pstate on this particular system.

Across the wide range of gaming tests, here is a look at the overall Ryzen 9 5950X RAPL-based power measurements for the entire duration. Using the ondemand or schedutil governors with AMD P-State saw a 12~13 Watt lower CPU power consumption on average for this particular Ryzen 9 5950X system but tended in many of the games with the Radeon RX 6800 XT to have much lower performance where any perf-per-Watt difference was a wash or in some cases worse off than the generic ACPI CPUFreq driver.