AMD, Nvida and intel I watch benchmarks for all GPUs. AMDs are the closest to their windows counterpart but its still around 10% roughly speaking. Keep in mind this is without ray tracing. If thats enabled linux is like 30% worse.
Nvidia is getting better I think they merged something recently that will help their vulkan pref match windows.
Nvidia is getting better I think they merged something recently that will help their vulkan pref match windows.