AMD P-State Driver To Premiere In Linux 5.17 With Aim To Deliver Better Power Efficiency
After going through several rounds of patch review the past number of months, the AMD P-State driver as an alternative to the common ACPI CPUFreq driver is going mainline. This AMD P-State driver relies on ACPI CPPC (Collaborative Processor Performance Controls) for making finer CPU frequency scaling / performance state decisions than what is afforded by ACPI CPUFreq. But because of the dependence on ACPI CPPC information, it only supports Zen 2 processors and newer. Additionally, CPPC functionality must be enabled by the system firmware/BIOS as well otherwise you will continue needing to use CPUFreq.
AMD-pstate is very promising for helping to boost the power efficiency of particularly AMD Ryzen desktop and mobile processors. Valve has been working with AMD on this driver in part to help the forthcoming AMD-powered Steam Deck handheld gaming console.
From late November you can see some of my recent AMD P-State Linux power/performance testing while when Linux 5.17 settles down in the weeks ahead I'll be running some fresh benchmarks on multiple systems.
As of yesterday the driver was pulled into the Linux power management subsystem's "linux-next" branch. With PM maintainer Rafael Wysocki now having pulled it into subsystem's "-next" branch, it will be submitted to mainline next week once the Linux 5.17 merge window is opened followed this weekend's release of Linux 5.16 stable. Linux 5.17 stable in turn should be out around the end of March but sadly will likely be too late for finding it in Ubuntu 22.04 LTS.