Combination, and it depends on the game. Dxvk will add latency, but depending on the renderer and how the game runs the reduction in CPU overhead by using dxvk instead of native can provide performance gains, especially on certain CPU's.

On games with a native vulkan renderer, Linux will most often just be faster since you have less system overhead burden. This has been fascinating to see though.

• First the games started to become playable, but framerates weren't so great.
• Framerates started to improve
• Framerates started to become a wash between Windows vs Linux
• We are progressing into this step: it either runs comparably or better.

The results are mixed right now, and it's going to be real hard to nail down predictability as far as performance goes. More often than not, so long as DRM isn't involved, games run really well on day one. Older games are starting to see a performance uplift and reliability improvements through proton/dxvk/vkd3d.

I'm very happy though that what we're talking about is comparable performance metrics. We use to be content if the shit ran at all.