Fossilize VS DXVKache

Note : AMD Propietary drivers for Vulkan on both Windows and Linux will have S E V E R E stuttering issues in game without fossilize shader precompilation. This is due to the lack of GPL support

Doesn't make a difference in download size at all, you don't download mesa shader caches (unless on Steam Deck, maybe), you download fossilize archives that are then compiled by the driver on your local machine. It will only affect the disk usage after it's compiled.

You're not the first to complain about fossilze (steam's shader precaching) freezing the system when processing, though I don't know why it would happen really to only some people - it must be some disk io or CPU scheduler shenanigans going on, since as you said, the GPU isn't really involved while compiling shaders.

Right, but this is part of Steam’s overall shader pre-caching system. From what I can tell when this window appears Steam is invoking their Fossilize library to do some work, possibly converting the cache from an intermediary representation to a usable binary for your hardware. I’m not sure why it only appears for some games, maybe it has to do with what graphics API the game is actually using and how the translation layer handles this. There is some discussion here but I couldn’t find official documentation (other than what’s in the Fossilize repository).

On Linux for the first run the game will precompile shaders thanks to this tool Valve made and open sourced. As a result we don't get shader stutter over here anymore.

These people seem to have the problem: https://github.com/ValveSoftware/Fossilize/issues/210

What the user below pointed out. Valve specifically uses a library called Fossilize (Open Source on GitHub here https://github.com/ValveSoftware/Fossilize) to generate the shader caches on your Steam Deck (or any machine running Proton).

Fossilize will only be helpful if it actually crashes while compiling pipelines, which I see no indication of in the bt, but still might happen I guess. Also it has some limitation with rt pipelines at the moment: https://github.com/ValveSoftware/Fossilize/issues/209 but still worth a try.

Almost all Steam games on Linux do this, it's really nice. Fossilize is an open source Linux tool made by Valve that precompiles Vulkan shaders. This only works with Vulkan though, so its use on Windows is limited, but basically everything on Linux runs through Vulkan, even DirectX games via DXVK.