AMD Ryzen 7 PRO 6850U: ACPI Platform Profile Low-Power vs. Balanced vs. Performance
As with many new Intel/AMD laptops these days, the recently launched Lenovo ThinkPad X13 Gen3 with AMD Ryzen 7 PRO 6850U "Rembrandt" SoC boasts ACPI Platform Profile support that is exposed under Linux for switching between low-power, balanced (default), and performance modes. For those curious about this ACPI Platform Profile impact, here are some benchmarks from this 6850U laptop under Ubuntu Linux and its impact on power and thermal efficiency too.
Separate from AMD's new work around a PMF Linux driver for Rembrandt, the Lenovo ThinkPad X13 Gen3 powered laptop features ACPI Platform Profile support so the user can choose between low-power and performance behavior of the platform itself. The Linux kernel has been preparing ACPI Platform Profile support over the past two years.
When it comes to Lenovo laptops specifically, Lenovo Platform Profile support was added in Linux 5.12. However, the initial support was busted for Lenovo AMD laptops but then fixed up a few months ago. With recent Linux kernels, the ACPI Platform Profile support for AMD Ryzen powered Lenovo ThinkPads should be working fine.
In my testing with the ThinkPad X13 Gen3, the Platform Profile support has been working out fine both via the sysfs configuration and through the convenient GNOME integration on supported laptops for run-time controlling between the low-power, balanced, and performance modes.
For this round of testing from the Ryzen 7 PRO 6850U powered ThinkPad X13 Gen3 with Ubuntu 22.04 LTS on Linux 5.19, I ran benchmarks when set to all three available ACPI Platform Profiles. No other changes were made during the testing process.