Windows v Linux, AMD 2990WX vs i9-7980XE
https://www.techspot.com/review/1683-linux-vs-windows-threadripper-vs-core-i9/
Intel honestly has the more solid CPU support for Linux right now. A few factors. One is of course the vast majority of the worlds Linux servers are running Intel hardware, its been very well optimized. Its also been very very well optimized by Intel themselves. Intel is one company that I am always torn on. I want to hate them most of the time... then I remember how much they really support Linux and open source. I guess no big company is all bad.
Having said that AMD has come a long way. They are not fully on board with their open source GPU drivers... and they are catching up with their optimizations for their Epyc and Ryzen chips.
Also keep in mind when you read Windows v Linux stuff... there are so many little things you can do to tweak performance under Linux. Their are entire distros such as Clear Linux with no goal other then extreme speed. (Clear Linux as an example is Intels own distro they maintain it for no other reason then to tweak max speed out of Intel hardware... they upstream what they learn and it improves Intel speed in any current kernel running distro) As more Linux server customers... and Linux gearhead programmers buy AMD. I would expect more performance will be squeezed out.
This is some interesting tests involving Linux Frequency Scaling Governor;
https://www.phoronix.com/scan.php?page=article&item=amd-2990wx-cpufreq&num=1
Here is some more windows v linux tripper testing for you;
https://www.phoronix.com/scan.php?page=article&item=2990wx-linwin-scale&num=1
To be fair though when talking about Gamers.... multi core is still not the promise land sadly.
https://www.phoronix.com/scan.php?page=article&item=threadripper-2950x-gaming&num=1