I guess the beefier your system is the less you will notice the impact of a greedy OS (because thats a fixed/absolute overhead) while the performance hit of having to translate directx through Proton will always be there (because that’s a percent-based overhead for each rendered frame)

So for the most top-end rigs, probably still Windows will squeeze a few more FPS. But it’s close.

At the end of the day Linux and Windows are both pretty comparable for gaming performance, so we shouldn’t worry about that as a deciding factor in which OS to choose, and can decide based on other merits.