I use Arch pretty much exclusively these days on my desktop, but this isn't quite true. Most of the time, Proton has a small performance impact (around 5% lower FPS), but some games tend to suffer more. For example Helldivers 2 runs around 10fps lower, which is pretty significant since I only got around 60-70 FPS on Windows at 4K (using a 3090).
Still, Proton is an amazing tool and these days it just works so well. The only games that don't work are those that are intentionally broken by invasive kernel-level anticheats. I won't be buying Battlefield 6, too bad for EA, there are now thousands of other games to play on Linux.
The general performance loss with the DX12 -> Vulkan translation on Linux especially with Nvidia hardware recently had the cause identified and will hopefully get solved in the near future. It has to do with descriptors and how Nvidia handles it is the general gist of it. A new Vulkan extension will be developed that more closely resembles how DX12 does things as I understand it, and then Nvidia and others can use that to hopefully solve this once and for all.
Here[1] is the full presentation and the slides[2] from it.
It means that at the very least the Nvidia specific performance loss of 10-20% will disappear. That is already not an issue with AMD cards as I understand it.
If it'll further increase performance beyond that remains to be seen. I suspect there will always be some amount of overhead, although at least with earlier versions of DirectX it is quite minimal already.
You’re comparing a game running on a compatibility layer, running on Linux to a game running directly on Windows. Not quite what the parent comment was stating.
There are few native Linux games, so performance on Proton is the essential benchmark. Besides, even when Linux native versions are available, the Windows version on Proton often offers a better experience (fewer obvious bugs).
I think grosswait is talking about the dx12 -> Vulkan translation layer. Running Windows games on Proton that use Vulkan get more comparable performance than Windows games that use dx12.
Still, Proton is an amazing tool and these days it just works so well. The only games that don't work are those that are intentionally broken by invasive kernel-level anticheats. I won't be buying Battlefield 6, too bad for EA, there are now thousands of other games to play on Linux.