Ryzen Mobile Power/Performance With Linux 6.3's New AMD P-State EPP Driver

Written by Michael Larabel in Software on 12 April 2023 at 01:00 PM EDT. Page 1 of 6. 34 Comments.

With Linux 6.3 there is the new AMD P-State EPP driver code for supporting the ACPI Energy Performance Preference (EPP) to further enhance the power efficiency and performance of modern AMD systems on Linux. Last week I ran some benchmarks of AMD EPYC with the new AMD P-State EPP mode while in today's article is a look at the laptop impact with Ryzen Mobile when comparing ACPI CPUFreq, the existing AMD P-State driver, and the new AMD P-State EPP mode and its multiple different preferences.

AMD Ryzen 7 PRO 6850U laptop

This round of testing is evaluating the new AMD P-State EPP option using a Lenovo ThinkPad X13 Gen 3 (LENOVO 21CM0001US) as the newest AMD Ryzen Mobile laptop I currently have available. This laptop is equipped with an AMD Ryzen 7 PRO 6850U "Rembrandt" SoC.

AMD Ryzen 7 PRO 6850U laptop

The Ryzen 7 PRO 6850U Linux CPU frequency scaling driver and governor comparison was carried out using a Linux 6.3 Git snapshot from last week. With Linux 6.3 the available different modes with each driver and governor combination (and EPP preference) included:

- acpi-cpufreq ondemand
- acpi-cpufreq performance
- acpi-cpufreq powersave
- acpi-cpufreq schedutil
- amd-pstate ondemand
- amd-pstate performance
- amd-pstate schedutil
- amd_pstate powersave
- amd_pstate_epp performance performance
- amd_pstate_epp powersave balance_performance
- amd_pstate_epp powersave performance
- amd_pstate_epp powersave power

A dozen different combinations that the current generation Ryzen / Ryzen Mobile hardware can currently operate in when it comes to the CPU frequency scaling drivers / governors / EPP preferences. With the upcoming Linux 6.4 cycle the AMD P-State Guided Autonomous Mode is also landing for yet more control over AMD power/performance on Linux.

AMD Ryzen 7 PRO 6850U AMD P-State Linux 6.3

With each of those combinations, dozens of different benchmarks were carried out on the ThinkPad X13 Gen 3 laptop while also monitoring the CPU power consumption, CPU peak frequency, and CPU thermals on a per-test basis.

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