Intel P-State vs. CPUFreq Frequency Scaling Performance On The Linux 5.0 Kernel

Those wanting to dig through even more benchmarks can do so via OpenBenchmarking.org.

As for the CPU thermal performance, CPUFreq powersave understandably led to lower operating temperatures considering the Core i9 9900K was pretty much bound to its lower performance states, leading to abysmal performance. The average Core i9 9900K temperature under load between the other driver/governor options was close to the same at 51~55 degrees.

When it came to the overall AC system power consumption throughout all of the benchmarks, consuming the most power on average was CPUFreq Schedutil and CPUFreq Ondemand. And as shown by the results their power efficiency wasn't even as competitive. Most Intel Linux users will be best off with either P-State's powersave (the default on most distributions) or performance governors.

Lastly is the geometric mean of all the benchmarks conducted showing similar leading performance between P-State/CPUFreq performance and P-State powersave coming in right behind.