Hi, I was doing some digging with an LLM using strace and perf, using the launch option WINE_NO_OPEN_FILE_SEARCH="models_building/textures" will tell Wine to simply return the files as not found instead of recursively searching, eliminating the loading times and meaning it now matches Windows.
Just tested this. Proton GE-11.3 was 17 seconds to load the test battle in rome using WINE_NO_OPEN_FILE_SEARCH="models_building/textures". Proton 11.0-2 still takes a long time though and WINEFSYNC_FUTEX2, PROTON_NO_FSYNC, and PROTON_NO_ESYNC didn't make a difference.
This looks like it might be a fix but no idea what GE is doing to make it quick. What version of proton are you using? Does anything break when you use that option for the campaign etc?
I forgot to add I’m using Proton-CachyOS-11 from Protonup-QT. I looked at the source of this particular repository with all sub modules with the help of an LLM and identified the WINE_NO_OPEN_FILE_SEARCH launch option. I mainly tested with city viewing but a city battle loaded pretty quick too.
`if (skip_search_cached == -1)
{
skip_search = getenv("WINE_NO_OPEN_FILE_SEARCH");
skip_search_cached = !!skip_search;
if ( skip_search_cached )
FIXME( "Disabling case insensitive search for %s\n", skip_search );
}
if (skip_search &&
strcasestr(unix_name, skip_search) &&
disposition == FILE_OPEN)
return `
I found out why this may only work with GE and derivatives
echo "WINE: -GAME FIXES- add file search workaround hack for Phantasy Star Online 2 (WINE_NO_OPEN_FILE_SEARCH)"
https://github.com/GloriousEggroll/proton-ge-custom/blob/master/patches/protonprep-valve-staging.sh?
Looks like this fix for PSO2 may have something to do with this.
Hm ok, I didn't realise that it was a GE only option. It probably just needs the same fix as #4122 then
After some days of Campaign playtime, I can confirm the game is running fine with this specific patch on proton-ge/proton-cachyos.
proton 11.0-2x1 2026-08WINE_NO_OPEN_FILE_SEARCHx2 2026-08WINE_NO_OPEN_FILE_SEARCH="models_building/textures"x2 2026-08PROTON_NO_ESYNCx1 2026-08PROTON_NO_FSYNCx1 2026-08WINEFSYNCx1 2026-08
Compatibility Report
System Information
I confirm:
steam-885970.log.zip
Symptoms
Loading screens for battles take an extremely long time on an NVME drive. The progress bar sometimes stays stuck at 0, sometimes part way through. Loading into cities takes upwards of 10 minutes which I can not find discussed anywhere for windows users. Using the linux version is not preferable as it crashes during campaigns.
Using strace you can see that there are a lot of fstat calls and the game searching for files which do not exist. Eventually this stops and the game loads very quickly after.
Reproduction
Custom battle in a city, try rome for example. See that the battle takes minutes to load even if the armies are very small, 1 unit each.
Small battles and those not in large cities will also take a long time but are much quicker.
It also happens if you just view a city on the campaign map without a battle