AMD Rembrandt CPUFreq vs. AMD P-State Linux Testing
Before getting busy with the AMD Ryzen 7000 "Zen 4" desktop testing, I recently wrapped up some benchmarks looking at the ACPI CPUFreq vs. AMD P-State frequency scaling drivers and various governor options for the AMD Ryzen 6000 "Rembrandt" mobile SoCs. If you are curious about the impact of CPUFreq/P-State and the various governors for the latest AMD laptops running Linux, this round of testing is for you.
Using the Lenovo ThinkPad X13 Gen 3 with AMD Ryzen 7 PRO 6850U "Rembrandt" SoC, I recently ran a number of CPUFreq/P-State tests for seeing the impact on performance and power consumption while running on battery power. This testing was carried out from the ThinkPad running an Ubuntu 22.10 development snapshot and running a Linux 6.0 development kernel at the time.
The tested configurations for this article included the:
- amd-pstate schedutil
- amd-pstate performance
- acpi-cpufreq schedutil
- acpi-cpufreq performance
- acpi-cpufreq ondemand
The same laptop was used for all of the tests with the same software stack besides changing out the CPU frequency scaling driver and governor in use. The Ryzen 7 PRO 6850U was running at its stock frequencies - the difference in the automated system table just comes down to base vs. turbo clock reporting via sysfs based upon the driver in use.
A wide variety of Linux workloads were tested for looking at the performance and energy difference for these various options on Linux 6.0.