The Impact Of The CPU Frequency Scaling Governor On AMD Threadripper 2990WX Linux Performance
One of many test requests we have received concerning the AMD Threadripper 2 Linux performance was to look at the impact of the different CPU frequency scaling governors, particularly for the 32-core / 64-thread Ryzen Threadripper 2990WX. Here are those CPUFreq governor benchmarks for those interested in squeezing slightly better performance out of your HEDT system by changing how aggressively or not the system is shifting power states to higher frequencies.
This testing is quite straight-forward and similar to our past CPUFreq comparisons (or the P-State CPU frequency scaling driver for Intel CPUs) in seeing the impact of the governors on the system performance. For this testing I didn't carry out any power consumption tests due to the WattsUp Pro being occupied in another system at the time and because if you are spending $1799 USD on a 250 Watt processor, chances are you just want maximum performance and are not looking for a balanced power profile under load or to be trying to achieve optimal energy efficiency.
The CPUFreq governors tested were conservative, ondemand, performance, powersave, and schedutil. The default CPUFreq governor on Ubuntu and most Linux distributions is "ondemand" while Clear Linux and a few others default to "performance" and then a select few use the new "Schedutil" governor that makes use of the kernel's scheduler utilization data in determining the CPU frequency scaling behavior. Granted, it's quite easy to change the CPUFreq/P-State governor for experienced end users. As a reminder, my launch-day Threadripper 2990WX tests were done using the performance governor across all tested CPUs. And then for the other articles/tests it depends whether it was an OS comparison of defaults or other factors as to whether the governor is overrode, but anyhow, the Phoronix Test Suite's automated system information tables always display this information for the reader.
The Linux 4.19 Git kernel in its early development state as of 18 August was used for benchmarking these CPUFreq governors. All benchmarks were carried out in a fully-automated and reproducible environment using the Phoronix Test Suite.