sombrezDoesn't the SteamOS/Linux version use OpenGL?
If so, why do the SteamOS benchmarks show that it has lower FPS than Windows?
OpenGL is quite outdated and has been inferiour to directx for years now wich is one of the reasons Vulkan is under development.
even with vulkan, if the game was programmed for directX from the ground up, translating the drawcalls to vulkan will result on a performance loss and driver overhead (see The Talos Principle)