Steam Beta adds Vulkan shader processing

Quoting: DadSchoorse

Quoting: rkfgFortunately, this format is standardized at the spec level so you can use the same shader cache on any GPU, be it AMD, NVIDIA or Intel and you won't need to rebuild it each time you update the driver (remember that pain with OpenGL?). It's not a problem for correctly ported games as the port developer (like Feral) can create a native SPIR-V cache ahead of time so the game just loads the shader it needs directly. That's why Shadow of the Tomb Raider runs so smooth natively and stutters like hell on DXVK.

You are misunderstanding what SPIR-V is. It's not something that the gpu can execute, it still needs to be combined with more pipeline state information and then optimized and compiled to the specific gpu's machine code. This is very expensive to do and causes the stuttering with DXVK. And that's where fossilize comes into play. It collects all pipeline state and all shaders to create the pipelines (basically gpu programs) and then Steam distributes them so that you can compile them for your specific driver and gpu outside of the game. That way the driver can cache the pipelines and doesn't need to compile them from scratch while you're playing.
As for why Feral ports don't stutter like DXVK, D3D11 doesn't give enough information on how a shader will be used before actually using it, that's why DXVK can only compile the pipeline when the game draws something with it. Feral know how shaders will be used since they have access to the game, so that's a big advantage.

Thanks, that's new to me! I thought SPIR-V is executed directly by the underlying driver since it's in the standard. But yeah, the very low hardware level is still different for every GPU so indeed some sort of translation happens under the hood. I didn't know the bottleneck is in the final compilation for the GPU. Good explanation, I was wondering why we need more preprocessing with this new feature if Steam already provides the cache. Now it's more clear.

Also, in the Fossilize README there's this:

QuoteThe goal for this project is to cover some main use cases:
<...>
Serialize state in application once, replay on N devices to build up VkPipelineCache objects without having to run application.

I think this is exactly what happens because when Steam is doing this new task there's a fossilize_replay process mentioned in nvidia-smi output. Would be really interesting to see how smooth it all is now out of the box, will try with a good-looking F2P game later.


Last edited by rkfg on 26 May 2020 at 11:43 am UTC

Quoting: Patola

Quoting: Leopard

Quoting: PatolaAny way to follow the shader transpilations that are occuring in the background?

Open up Steam's settings - Shader Caching

It will show an estimate time about finishing the current game it compiles shaders with showing the name of game also.

Wow.
I just bought a new 8 TB disk and then moved my games logical volume to that disk and resized it from 3 to 6 TB. Then I installed basically every game I have on Steam (~620). Got only a few hundred GB left.
Judging from the pace I am seeing, it will take a few days to finish... Will it do that to every installed game?

It depends on how many shaders those games have+ if those actually have Foz pipelines cached on Steam + if you have a NV gpu or AMD

At the moment , for AMD if you click on "run the game " it will go into full blast mode which means it will do that building task multi threaded. Still single threaded on NV but hopefully should be fixed at the upcoming weeks.

I turned off shader pre-caching so long ago because whatever benefits it was supposed to impart were offset by having it interfere, waiting for downloads just before playing a game (or something like that ... it's been so long I can't even remember what the problem was exactly) :P In fact I don't even remember what shader pre-caching was even for --- lol. Nevertheless, it sounds like this is a nice thing.


Last edited by Nanobang on 26 May 2020 at 12:38 pm UTC

Does it work for Windows too ? Or there is already something similar ? Just curious...

Great feature. Thanks Valve!

I noticed this issue on Crucible. I really want to see how it will work on my XR 5700 XT.

I'll be interested to see if people notice differences.

Quoting: Purple Library GuyI'll be interested to see if people notice differences.

I saw a huge improvement on Quake Champions which is nearly bad as Warframe and Path of Exile about shaders.

It was smooth af.Previously, it wasn't the case , lots of stutters that makes the game literally unplayable.

Quoting: GuestWhen they first introduced this shader caching/sharing thing Steam started to download hundreds of megabytes of shaders… not a very slight increase in disk and bandwidth usage, no. So I disabled it right away…

If you prefer stutter and freezes every time something new appears on screen then yeah. But I don't think it's worth it. If you play games with a lot of shaders (= AAA games) you'd better invest into a bigger and faster SSD because the rest of your hardware should already be quite good. Honestly, bad first time experience isn't worth the saved disk space.

Quoting: Guest

Quoting: rkfgIf you prefer stutter and freezes every time something new appears on screen then yeah. But I don't think it's worth it. If you play games with a lot of shaders (= AAA games) you'd better invest into a bigger and faster SSD because the rest of your hardware should already be quite good. Honestly, bad first time experience isn't worth the saved disk space.

No, I don’t have that problem. And I have 5TB of SSD for games.

It depends on the game and mostly applies to non-native ones. If you don't play them probably you're fine. But some games stutter much more than the others and if you have plenty of space why not download those caches? Also you will help other players by uploading your cache back. It's like torrents but 100% legal!