Our latest Ryzen Linux benchmarks are looking at the impact of the CPUFreq scaling driver's governors have on the performance of the Ryzen 7 1800X, including a look at the power consumption and performance-per-Watt when changing the governors.
ACPI CPUFreq is what takes care of the CPU frequency scaling for AMD Ryzen processors on Linux to switch between the high and low-power states depending upon load (there isn't any AMD-specific driver for modern AMD CPUs, unlike Intel's P-State driver). On most Linux distributions like Ubuntu, ondemand is the default CPUFreq governor. For this article I tested the Linux 4.10 kernel with CPUFreq's ondemand, performance, schedutil, powersave, and conservative governors. Some basic/quick information about the each of them:
Ondemand - Commonly the default, it scales the the driver based on current load and will usually go to the highest state then dropping back as deemed appropriate.
Performance - Aiming for running the CPU at its maximum frequency.
Schedutil - Schedutil is the newest governor and it's about making use of information from the Linux kernel's scheduler to try to better change the CPU frequency in a timely manner based on the scheduler utilization metrics.
Powersave - Powersave is a common governor for those looking to extend their battery life or reduce power consumption by running at the lowest frequency state for longer periods of time.
Conservative - This is similar to powersave in its approach and prefers running at lower frequencies for longer periods of time.
These tests happened on the AMD Ryzen 7 1800X system while using the Linux 4.10 kernel with Ubuntu 17.04 x86_64. During the testing process, the Phoronix Test Suite was monitoring the AC system power consumption using a WattsUp Pro power meter and also auto-generating performance-per-Watt data points.