Check out Proton-Sarek if you have an older GPU for Windows games on Linux

Valve's work with Proton to run Windows games on Linux / Steam Deck is amazing, but they do require you have newer GPUs so some have been a bit left behind. Proton-Sarek aims to fix that.

What is it? A community built version of Proton (like GE-Proton) designed specifically for those of you who have a GPU that doesn't support newer Vulkan, or with no Vulkan support at all but still want all the latest updated from Proton to keep gaming on Linux.

As the developer explains on the GitHub page:

Because there are still users with GPUs that support Vulkan 1.1+ but not Vulkan 1.3, as well as others with non-Vulkan support. Those who can use DXVK often rely on older Proton versions, which suffer from lower compatibility and performance compared to newer builds. Meanwhile, users dependent on WineD3D frequently face poor gaming experiences. This repository provides patched versions of Proton and/or Proton-GE, offering better performance with DXVK v1.10.3 and WineD3D mainly through the custom parameter PROTON_TWEAKS, along with other enhancements, ensuring a smoother experience for both Vulkan and non-Vulkan setups.

Seems like a nice idea for older systems. And much like GE-Proton, there's no support from Valve for this, but it's useful if you need it.

The developer recently released Sarek 9-18 and 9-17 with the base of the project updated to GE-Proton 9-17. On top of that it includes two new options:

• PROTON_VK_SOFTWARE: Uses Lavapipe to enable CPU-based rendering for Vulkan, supporting API version 1.3.
• PROTON_OGL_SOFTWARE: Uses LLVMpipe to enable CPU-based rendering for OpenGL, supporting API version 4.6.

See more on the GitHub page.