Radeon+Ryzen CPUFreq CPU Scaling Governor Benchmarks On Linux 4.15
Taking a break from KPTI and Retpoline benchmarks, here are some tests recently conducted with Linux 4.15 when it comes to trying out the different CPUFreq scaling governors with this latest kernel and running various games with a Radeon RX 580 Polaris graphics card.
With the CPUFreq (and on the Intel side, P-State) CPU frequency scaling drivers continually being refined along with other power management improvements, these tests are basically the latest numbers for reference purposes for those curious about the current impact when gaming.
The CPUFreq governors tested with this Ryzen 7 1800X system included Ondemand, Performance, Schedutil (makes use of the scheduler's utilization data, the newest governor option), and Powersave. Ondemand is the default CPUFreq governor on Ubuntu and most other distributions out there. Linux games (particularly Vulkan titles) generally recommend using the Performance governor. Powersave is generally what's recommended if you want to save power, i.e. for a Linux laptop, at the cost of reduced performance.
With this being a desktop system and generally gamers just caring about getting the best performance, I didn't do any AC system power measurements this time around (as well as because my lone WattsUp power meter was busy on another system) and solely looking at which governor is yielding the best performance and the games where changing from the "ondemand" default governor may be worthwhile.
These Ryzen+Radeon Linux 4.15 with Mesa 17.4-dev tests were done using the Phoronix Test Suite with a range of OpenGL and Vulkan games.