Linux Steam : 700 - 800 MB shader-pre cache is re-downloaded after every restart

[-=FL=- UniversE]

Every time I start Steam the game downloads 700 to 800 MB shader pre-cache.

Before I moved to a region where fibre channel is not yet built, I did not notice. But now that I am down from 200 Mbps to 2.5 Mbps downstream, it is quite impactful and painful.

Version and language
Steam on Linux - English, newest stable version

Whether or not your game is modified
No. In particular no workshop items subscribed.

Game start being played.
Irrelevant.

Exact nature of the problem
see above

Any possibly relevant changes you have made
No. In particular when I let the download complete successfully and don't even start the game, the next time I start Steam, it happens all over again.

Your system specifications in the form of a DxDiag report and vulkaninfo
https://uap-core.de/misc/vulkaninfo

[Alan Phipps]

I don't know if anything here might help.

[-=FL=- UniversE]

Maybe - I can try.

In the meantime, I tracked down the problem a bit.

It looks like there is a big fat 800 MB file with all the cached shaders. It's this one:

.steam/steam/steamapps/shadercache/392160/fozpipelinesv6/steam_pipeline_cache.foz

I can at least confirm that immediately restarting steam after the download completes, the re-download does not happen. So at least the very nature of a "cache" seems to be intact.

So here is what I am guessing: since it's just a single file, even one byte changed will cause this one single file to be re-downloaded entirely. I don't know how often and why the remote version of that file would change, but if it does, it would explain everything.

As a quick-fix I could just disable pre-cache entirely, until I can get rid of my 90s internet. But maybe someone wants to investigate if it's intended that the file changes quite frequently and causes these huge downloads. Even with fiber channel internet, I think it's a good idea not to waste traffic.

Let's see if my theory holds. Here is the sha256 hash from the file today: be9244be5b1d8eaa708d64bc0c797e155daac963588bb7d49f0b2a2bf78b9cdf

When it's different after the next re-download, I think my theory is confirmed. If it's not, then something might be wrong with my steam installation and I will try deleting the pipelinecache.bin file as suggested in the other thread.

[-=FL=- UniversE]

Okay, mystery resolved.

The good thing: it's not always a full 700 MB download.

Today the download was 250 MB - still a bit painful, but not as bad as always downloading the entire file.

The sha256sum of todays cache is 68cfdf1e4088dbb97d8e03a75730040271e198e0632eec54a0bb21a5ff831492.

Now the two questions are:

1. Is it intentional that this file changes on a day to day basis?

2. Is this 100% steam magic or is there anything Egosoft can do to influence what's happening there?

If the answer to (2) is: yep, 100% Steam, nothing we can do, this thread can be closed and I have to disable shader pre-caching.

[Imperial Good]

Make sure you are running the Linux build of X4, and not accidently running the Windows version via emulation on Linux. I recall that for some reason a lot of Linux steam users end up running the emulated windows version by default. If running the windows version via emulation it could be caused by Valve updating their Windows emulation layer.

[Rinne]

Hi UniverseE,

this is a known Steam Client issue on linux. It has been coming and going for a couple of years now.
Here is the github issue: https://github.com/ValveSoftware/steam- ... ssues/8076

I can confirm it's happening for me as well.

[-=FL=- UniversE]

So a Steam bug on Linux, then. How sad. But then there is nothing, Egosoft can do

Thank you for the pointer to the github issues.