+1 to the frame stutters on Proton Experimental.

I'll also note that I had issues with the steam overlay on Proton 9 that were fixed by using Proton Experimental.

I've talked with a few others who own the game and managed to reduce the stutters substantially. I performed some changes in my nixos config, which can be found in this PR. But I honestly cant say what helped.

On another note, if you're having heavy stutters in the open world, you might want to disable rebar either through the bios or using VKD3D_CONFIG=no_upload_hvv. If this game is anything like elden ring, it wont like having rebar on.

Before changes:

After changes:

While the screenshots arent exactly in the same place, the stutters would happen regardless where I was in the level. The frame time pacing could be better, but unless you use a mouse like me, you wont notice them.

I didn't see any improvement from VKD3D_CONFIG=no_upload_hvv %command%. I'm using a Radeon 7900 XTX

It seems anecdotally that the frame stutter I'm seeing is in the areas where shrubbery "glows" a bit (but only sometimes). It kind of feels like shader cache-ish issues, but also not quite.

Also ... I should note the additional problem that I had to go to "borderless fullscreen" to get 4k resolution available. The normal fullscreen mode didn't list anything higher than 2k on the resolutions. I'm unsure if the game simply doesn't support 4k natively (seems unlikely) or if this is some Linux specific bug.

I think borderless fullscreen and fullscreen are effectively the same under Linux anyways; but it seemed odd.

Edit: See this comment on how to fix the issue.

Something weird is going on with this game. When I first load into the roundtable hold, I have pretty bad performance for a few minutes, at which point the frame timings will stabilize and performance increases.

Then, as soon as I go into matchmaking, the frame timings become absolutely terrible again, until I leave matchmaking. This continues while playing in a lobby. This doesn't seem to happen in singleplayer.

Seems like other people have the same issue as well.

https://github.com/user-attachments/assets/1f88779f-510c-464a-8875-6502c0e4494e

OS: NixOS 25.11.20250528.96ec055 (Xantusia) x86_64
Host: Gigabyte Technology Co., Ltd. Z690 UD AX
Kernel: 6.15.0
Uptime: 38 mins
Packages: 1556 (nix-system), 8237 (nix-user)
Shell: fish 4.0.2
Resolution: 3840x2160, 1920x1080, 1920x1080, 3440x1440
DE: Hyprland (Wayland)
Theme: Layan-Dark [GTK2/3]
Terminal: zellij
CPU: 13th Gen Intel i7-13700KF (24) @ 5.300GHz
GPU: AMD ATI XFX Speedster MERC319 Radeon RX 6950 XT
Memory: 15548MiB / 31928MiB

Edit: Something really magical is going on here. Disabling all E-Cores, Intel SpeedShift, and Hyperthreading seems to have helped. You can see performance still drops once in a lobby, but significantly less than before.

https://github.com/user-attachments/assets/fab3b110-ef36-4bcd-88cd-e72ddaad7dab

So, I looked into the frame drop situation a bit more. It appears the frame drops are not exclusive to Linux.

I have a friend who on Windows had some issues tonight. I also saw in the patch notes frame rate issues acknowledged.

https://en.bandainamcoent.eu/elden-ring/news/elden-ring-nightreign-patch-notes-version-101?utm_source=SM_Official&utm_medium=official_post&utm_campaign=ER-NIGHTREIGN-Patch101

Got a hard crash after more than 10 hours, not sure where to report it

Arch Linux
AMD 7800XT+
Kernel 6.14.9-zen1-1-zen
Mesa 25.2.0-devel (git-e942d1e9e4)

jun 01 20:12:08 artorias kernel: amdgpu 0000:03:00.0: amdgpu: Dumping IP State
jun 01 20:12:08 artorias kernel: amdgpu 0000:03:00.0: amdgpu: Dumping IP State Completed
jun 01 20:12:08 artorias kernel: amdgpu 0000:03:00.0: amdgpu: ring gfx_0.0.0 timeout, signaled seq=42669327, emitted seq=42669329
jun 01 20:12:08 artorias kernel: amdgpu 0000:03:00.0: amdgpu: Process information: process nightreign.exe pid 24445 thread vkd3d_queue pid 24700
jun 01 20:12:08 artorias kernel: amdgpu 0000:03:00.0: amdgpu: Starting gfx_0.0.0 ring reset
jun 01 20:12:10 artorias kernel: amdgpu 0000:03:00.0: amdgpu: MES failed to respond to msg=RESET
jun 01 20:12:10 artorias kernel: [drm:amdgpu_mes_reset_legacy_queue [amdgpu]] *ERROR* failed to reset legacy queue
jun 01 20:12:10 artorias kernel: amdgpu 0000:03:00.0: amdgpu: Ring gfx_0.0.0 reset failure
jun 01 20:12:10 artorias kernel: amdgpu 0000:03:00.0: amdgpu: GPU reset begin!
jun 01 20:12:14 artorias kernel: amdgpu 0000:03:00.0: amdgpu: failed to suspend display audio
jun 01 20:12:17 artorias kernel: amdgpu 0000:03:00.0: amdgpu: MES failed to respond to msg=SUSPEND
jun 01 20:12:17 artorias kernel: [drm:amdgpu_mes_suspend [amdgpu]] *ERROR* failed to suspend all gangs
jun 01 20:12:17 artorias kernel: amdgpu 0000:03:00.0: amdgpu: suspend of IP block <mes_v11_0> failed -110

Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2926780521

Do you mean general frame drops or specifically when in a multiplayer lobby? It seems like not everyone has the strange issue that performance tanks when in a lobby and immediately recovers when leaving again. I don't have this issue on windows.

Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2927781274

I haven't "felt" any performance issue in a multiplayer lobby personally. It's possible there's been one, but nothing observable using a controller and no FPS counter.

I have had frame stutter in a match that's best described as the game occasionally looking like a projector for the 40s. It's neither fluid nor choppy but somewhere in the middle, almost like a laggy slow-motion effect; that's what I'm referring to.

in both windows & linux (dual boot windows 11 + Fedora KDE 42), I get uncharacteristically terrible performance on my rig (7900XTX, i9 12900k, 32GB DDR4 3200mhz, installed on SSD).

On windows, with a hex edit to unlock FPS, I was getting swings from about 120 fps -> sub 60 fps, VERY jumpy and laggy. on Linux with unlocked FPS, similar story. with locked FPS on either OS, I stay around 45~ fps with about 50% GPU usage, which sometimes briefly goes back to a nice 60fps, but returns (same behavior as many others are having)

on Windows, I was able to completely fix this issue by following these steps (disabling core parking):
https://www.reddit.com/r/Eldenring/comments/1dhkgua/psa_if_your_elden_ring_is_stuttering_on_pc_try/|

which made my uncapped FPS stay pretty rock solid around 120fps+, as you would expect (and 60fps while capped with no drops, of course). this makes me think it's a 12th/13th/14th gen intel CPU issue, except for the fact that my brother, with an AMD cpu (and GPU, 6950xt) is also getting sub 60 fps (30~ or lower) on his windows rig... very strange.

Regarding performance in case it helps:

CPU 7800X3D
GPU 7800XT
32 GB Ram
Installed on NVME SSD

No problems on the roundtable. The framepacing is not perfect but I can play without a problem. When on the map, I have from time to time (I would say random) like 5-6 seconds the game goes to 10-20 fps, and then comes back to 60, no idea whats going on there.

Then on some bosses with lots of effects, there are frame drops but I've seen that happening on WIndows too to some streamers.

Patch should be dropping right now, lets cross fingers it fixes this a bit.

Elden Ring Nightreign exhibits significantly degraded performance on Linux through Proton compared to native Windows performance. Game runs at 30-45 FPS with severe stuttering in boss rooms (10-20 FPS), while Windows achieves consistent 60 FPS. GPU and CPU utilization remain unusually low.

System Specifications

• OS: Arch Linux x86_64
• Kernel: Linux 6.15.0-2-cachyos
• Desktop Environment: KDE Plasma 6.3.5
• CPU: AMD Ryzen 9 3950X (32 cores) @ 4.76 GHz
• GPU: AMD Radeon RX 7900 XTX
• Memory: 31.26 GiB
• Display: M28U - 3840x2160 @ 144Hz (scaled to 2560x1440) 31" [External, HDR enabled]
• Mesa Version: Mesa 25.2.0-devel (git-3ba9038648)
• Storage: Installed on NVMe SSD

Game Information

• Game Version: 1.01.1
• Installation: Steam
• Note: The new version update from today doesn't seem to fix this issue

Proton Versions Tested

• Proton GE 10.3
• Proton GE 10.4
• Proton Experimental
• Proton Hotfix
• CachyOS Proton 0520
• CachyOS Proton 0601

Result: Consistent poor performance across all tested versions

Performance Issues

Frame Rate

• Linux (Proton): 30-45 FPS average
• Windows (Native): 60 FPS consistent
• Boss Rooms: Severe drops to 10-20 FPS with heavy stuttering

Resource Utilization

• GPU Usage: ~60% maximum (significantly underutilized)
• CPU Usage: ~20% maximum (significantly underutilized)
• Graphics Settings: No performance improvement when lowering from high to low settings

Attempted Solutions

Current Steam Launch Options

VKD3D_CONFIG=no_upload_hvv VK_DRIVER_FILES=/usr/share/vulkan/icd.d/radeon_icd.i686.json:/usr/share/vulkan/icd.d/radeon_icd.x86_64.json RADV_PERFTEST=gpl,rt mangohud gamemoderun %command%

Graphics Settings

• Tested all settings from Ultra to Low - Result: No meaningful performance difference

Expected vs Actual Behavior

• Expected: Performance similar to Windows (60 FPS) with proper GPU/CPU utilization
• Actual: Severely limited performance with hardware underutilization

Additional Context

• Issue appears to be game-specific as other titles perform adequately

Screenshots

Update :

I found a way to have 60fps now. I was in rusty scheduler in sched-ext

I have change it to scx_pbfland, Profile : Gaming with extra scheduler flags : -m performance

Sometimes I get drop to 56/58 fps but its now playable.

reply to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2925783351

I've encountered another issue. At times when opening menus like bonfires to level, merchants or boss rewards, my game can at times freeze for halve a second. There is for sure something funky going on with this game.

I feel like there are two different issues at play here:

Generally sub-par performance

This can seemingly be alleviated by disabling intel core parking, using a performance governor, disabling e-cores, etc.
This same issue plagues base Elden Ring, so it seems this was never improved on.

Performance degradation in multiplayer sessions

Edit: See this comment on how to fix the issue.

I have no idea why some people have this and others don't. I don't even have the issue on the same hardware under Windows.
As soon as the session is online the game does something which tanks performance. As soon as that thing stops, performance increases again. You don't even have to be in-game, you just need to open a lobby to observe this for those affected.
I've tried the following, of which nothing helped:

• Disabling Intel PState
• Disabling E-Cores
• cpupower frequency-set --governor performance
• Switch to scx_bpfland
• Tried proton experimental, bleeding edge, hotfix, various GE versions, etc

The issue can also be seen when starting the game in offline mode. When this is done, it immediately runs at 60 FPS, indicating that initially bad performance in online mode isn't related to shader compilation or something along those lines, it's likely something network related. You can even see the degradation happening in the main menu when going online, without even being in-game.

Here's a video where I first start in offline mode with some mild frame-pacing issues (but certainly playable), and then switch to online mode which absolutely tanks performance. It then recovers after a short while, and then becomes worse again when joining a lobby, and better when disbanding it.

https://github.com/user-attachments/assets/bcd4c766-f880-4efa-acd6-8ea17f656ccb

I don't know if this is an Intel specific problem since for me the game works perfectly fine on an AMD platform.
No performance issues whatsoever on both Proton Hotfix and Proton Experimental.
No tinkering was required, just downloaded the game and started it. Stable 60 FPS in all situations.

My system:

• Arch Linux, kernel 6.14
• KDE Plasma with wayland
• RTX 3080 10GB - nvidia-open-dkms driver
• Ryzen 7 5800x3d
• 32GB DDR4

Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2944265053

Yeah, it's very strange. There's a few reddit threads on the multiplayer issues, and all of those are 12th, 13th, and 14th generation intel processors. Could be a coincidence though, because there's also someone on an AMD processor having the same issue.

If the processor is the issue, it also doesn't explain why it runs perfectly fine under Windows using the same hardware...

Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2944265053

I think the lobby thing may be; the frame stutter does happen for me on an all AMD system.

If you haven't had any frame stutter, perhaps there's a mesa issue and an Intel issue that makes the mesa issue worse.

Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2945179706

For the frame stuttering, check if you have the same behavior in base Elden Ring if you own it, it used to be an issue there as well, and I am assuming it was never fixed. The multiplayer stutters are new though as far as I know...

• OS: Arch Linux x86_64
• Kernel: Linux 6.14.9.arch1-1
• Desktop Environment: Hyprland
• CPU: 12th Gen Intel(R) Core(TM) i9-12900K (16+8) @ 5.20 GHz
• GPU: NVIDIA RTX 3070
• Proton: GE-Proton10-4

Finally able to get full 60fps in multiplayer with 0 stuttering or frame drops.

My solution was as follows;

1. Disable intel_pstate in your bootloader, for me this is GRUB: sudo nvim /etc/default/grub and add intel_pstate=disable to GRUB_CMDLINE_LINUX_DEFAULT=
2. Install gamemode and lib32-gamemode: sudo pacman -S gamemode lib32-gamemode EDIT: and set your usergroup for gamemode: sudo usermod -aG gamemode YOURUSER
3. Now here's the tricky part, using gamemoderun in the launch options causes a crash after the EAC splash screen (at least for me) so open up a terminal and use gamemoded -r this will start a gamemode session across all processes.
4. Launch Elden Ring: Nightreign
5. ???
6. Profit

When you're done playing just CTRL+C to stop gamemode in your terminal.

Why does this issue occur? I'm not really sure, but launching the game leaves my Intel CPU in a powersave state rather than allow my kernel cpu governor to change it at all. Is this specific to 12/13/14th generation CPU's? I think so. I also think this may happen on newer AMD CPU's.

The only issue that I can't seem to rectify now is that if I move to another workstation it will cause FPS in Nightreign to halve and then cause a "Framerate Unsuitable for Online Play" error to boot you from multiplayer. As long as you stay within the game window it's smooth sailing though.

Edit: I don't even know how I fixed the changing workspace issue but after swapping between fullscreen/borderless to fix some blurry textures it just fixed itself. Games wonky but hey it works. Fully playable online at 60fps, can switch workspaces, no issues. I think the game just needs to be in focus on at least 1 workspace to not encounter the unsuitable framerate issue.

Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2945876353

gave this a shot, to no avail unfortunately :/ game continues to never exceed about 48 fps (except for a few seconds every now and then pretty randomly)

OS: Fedora Linux 42 (KDE Plasma Desktop Edition)
KERNEL: 6.14.8-300.fc42.x86_64
CPU: 12th Gen Intel Core i9-12900K
GPU: AMD Radeon RX 7900 XTX (radeonsi, navi31, LLVM 20.1.3, DRM 3.61, 6.14.8-300.fc42.x86_64)
GPU DRIVER: 4.6 Mesa 25.0.6
RAM: 32 GB

In my case, even after running Gamemode in a separate terminal, it didn't attach to the game, maybe it's somehow related to this

Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2946429802
Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2946375373

Type gamemoded -t in a terminal to check if gamemode is able to set your cpu governance. If output says the test fails you need to do this: sudo usermod -aG gamemode YOURUSER

Updated my original comment to reflect this.

Type gamemoded -t in a terminal to check if gamemode is able to set your cpu governance. If output says the test fails you need to do this: sudo usermod -aG gamemode YOURUSER

no luck, unfortunately (all tests pass, performance is still scuffed).

idk if it's worth noting, but I don't need to do gamemoded -r because my game doesn't crash with gamemoderun %command% (although i did test both individually & together, no difference)

EDIT: wait. i think I'm wrong. further testing and the sub 60fps is gone, i appear to be set at 60! I'll have to test in an online game again as well. weird.

Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2948013490

I don't think running the game with gamemode works, because the EAC splash will have gamemode on according to mangohud, but mangohud reports the game not running with gamemode as soon as it launches. So it will likely require running gamemoded -r to launch it with gamemode correctly.

This removes any of the network related lag issues I have (thanks @NuLLxD !).

The only very annoying issue I am left with is that the game will run flawlessly for ~20 minutes, and then at some random point in the run it will suddenly have terrible frametime until I restart the game. I don't know what triggers this (nothing specific in the game is happening), and the bad frametimes are very consistently bad (e.g. one normal frame, one delayed frame).

Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2949360486

Sounds like https://github.com/ValveSoftware/steam-for-linux/issues/11446

Glad to help @SchnozzleCat. Try adding LD_PRELOAD="" to your launch options. Game should run like butter.

If anyone views this thread and finds the information here has solved their issue please take the time to react to my initial https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2945876353 so that the solution is clear to people visiting the thread for the first time.

Replying to [#8751 (comment)](https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2945876353)

Can't get the crashing to stop, even after powering off my system and powering it back on, or doing the LD_PRELOAD="" fix mentioned later.
gamemoded -t passes all tests too

• OS: Arch Linux x86_64
• Kernel: Linux 6.14.10.arch1-1
• Desktop Environment: Hyprland
• CPU: 12th Gen Intel i7-12700K (20) @ 4.900GHz
• GPU: NVIDIA GeForce RTX 3080 Ti
• Proton: Proton Experimental

https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2951965957

@mitterdoo Can you explain what you mean by crashing? Crashing during EAC splash? Crashing in game after some time? Crashing at startup before EAC?

Specifically the crash after the EAC window closes. After that, the game opens to a white screen for about 5 seconds, then closes

https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2952091859

What launch options are you using? Have you tried without any launch options? Try going to your library and searching for "Runtime", Proton EAC Runtime should pop up and you should install it if you haven't.

You could also try adding env -u SDL_VIDEODRIVER to your launch options.

OS: Arch Linux
KERNEL: 6.14.10-arch1-1
CPU: 13th Gen Intel Core i9-13900K
GPU: NVIDIA GeForce RTX 4080
GPU DRIVER: NVIDIA 575.57.08
RAM: 64 GB
DESKTOP: KDE Plasma 6 (Wayland)

Issues with default setup

• Bad performance, stutters, CPU/GPU underutilisation
• Typically 40-50fps solo, randomly 60, multiplayer caps to 30fps

The fix

Add yourself to gamemode group

sudo usermod -aG gamemode $(whoami)

Relogin to your desktop.

Run gamemoded in a separate terminal

gamemoded -r

This applies to everything unlike gamemoderun in launch options (which crashes anyway).

Launch the game normal launch options

MANGOHUD=1 %command%

After fixes

With these I achieve a stable 60fps with max settings. No frame timing issues.

No other modifications are needed (for me). Other suggestions in this thread did not work.

Random short stutters still persist. Could be a shader caching issue. The game launches some ten .exe processes when playing online and that with some bugs could be the reason behind abysmal CPU scheduling by default.

Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2952786748

"Other" suggestions did not work. "That" suggestion did. 🤓

I see now that I may have replied in haste, however this exchange is really funny.

[#8751 (comment)](https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2952121126)

Aha, good callout. I had gamemode %command% in my launch options before I tried this fix; i see you didn't actually say to add that to the launch options.

Sure enough, I left the launch options empty and ran gamemoded -r prior to launch, and it didn't crash, and i could go into a multiplayer lobby just fine without any FPS issues. I even found that you can run the command at any time, either before launch or while the game is running.

thank you!!

[#8751 (comment)](https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2952922775)

aha! removing gamemoderun from the launch options entirely (as was recommended to me lol), along with running gamemoded -r properly fixed the issue, i no longer switch between 48 and 60 fps, just a nice solid 60!

System Specifications

OS: CachyOS x86_64
Kernel: Linux 6.15.1-5-cachyos
DE: KDE Plasma 6.3.5
WM: KWin (Wayland)
CPU: 13th Gen Intel(R) Core(TM) i7-13700HX (24) @ 5.00 GHz
GPU 1: NVIDIA GeForce RTX 4070 Max-Q / Mobile [Discrete]
GPU 2: Intel Raptor Lake-S UHD Graphics @ 1.55 GHz [Integrated]
Memory: 15.35 GiB

So what seems to have worked for me was disabling split lock via Cachy OS' guide, will just quote it here since the wiki was down when I went to link it. I don't get any terrible framedrops any more and the GPU usage has now increased past the 30% max I was seeing before. I have a feeling the reason why gamemode is the fix for most people is due to the fact that it disables split lock, but this is a more permanent fix.

CachyOS Guide

Disabling Split Lock Mitigate

In some cases, split lock mitigate can slow down performance in some applications and games. A patch is available to disable it via sysctl.

Disable split lock mitigate: sudo sysctl kernel.split_lock_mitigate=0
Enable split lock mitigate: sudo sysctl kernel.split_lock_mitigate=1

To make the change persistent, add the following line to /etc/sysctl.d/99-splitlock.conf:

kernel.split_lock_mitigate=0

For more information on split lock, see:
https://www.phoronix.com/news/Linux-Splitlock-Hurts-Gaming
https://github.com/doitsujin/dxvk/issues/2938

In typical from software fashion, you fix one issue and two more pop up. Somehow, I'm now experiencing seconds long freezes in the game when playing online, I cant say why this is happening and it seems to be a new development. This already started happening before the latest update, but I thought it might just be my compositor doing something crappy, but it also happens on gamescope. I genuinely cant tell whats going on and at this point I dont even want to bother with it.

Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2963975955

I don't believe this is an issue specific to you as I've seen this reported in various places on various setups. Could you post the output of vulkaninfo --summary? I'd like to have a look, might go nowhere though as I don't have an AMD card nor much knowledge of AMD configurations.

I've also noticed you use the envar "SDL_VIDEODRIVER,wayland" and the launch option SDL_VIDEODRIVER=windows it may be worth unloading the driver entirely and then letting it fallback (?) with env -u SDL_VIDEODRIVER. Probably just rambling at this point.

reply to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2964013295

This would be the output of vulkaninfo .

I'll unset the SDL variable and see how things go. That said, I checked my kernel messages and it seems that lavd fails to starts for up to 35s, which kinda lines up with the freezes when it comes to time stamps. I switched to bpfland and it seems to have solved the freezes, but now the frame times are less stable (basically back to my starting experience).

Edit: It seems that nightreign really doesnt like the scx schedulers. Running bpfland caused uneven frame times and lavd seems to straight up cause freezes. I tried to run the game without any of them active by simply killing the current active scheduler (in this case bpfland with -m performance) and the frame times seem to be extremely smooth now. I still have to test online.

I can confirm using lavd scheduler, after latest update is generating game freezes.

reply to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2981947446

I took a look at the scx repo and it appears that this was a known problem. The itself is closed, but based on what we've experienced, this doesnt seem to be fixed, or it came back. Here is a link to the scx issue in question.

While the game runs flawlessly for me, Steam's game capture only captures the initial EAC popup. This might affect other EAC games as well

E: Looks like it's related to this https://github.com/ValveSoftware/Proton/issues/5794. Experimental seems to fix it

Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2945876353

I've been trying to solve the same issue and, although the game runs at around 60fps, it has major stuttering issues when in solo or multiplayer runs. Did your solutions fix it completely or is your game running similarly to how mine is?

setup:
i5-12400 ----------- Arch Linux x86_64
rx 7800xt ----------- Linux 6.15.4-arch2-1
32gb (4x 8gb) -----------KDE Plasma 6.4.1 (Wayland)
Installed on SSD ----------Bootloader= Systemd
Proton-GE

variation to your solution:
-->instead of changing GRUB_CMDLINE_LINUX_DEFAULT= I added intel_pstate=disable into /usr/share/systemd/bootctl/arch.conf
-->added VKD3D_CONFIG=no_upload_hvv gamemoderun %command% to launch options

• in console used sudo echo performance | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governorecho performance | tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
  Desired result:
  -Making the game run at a stable fps (even if it means switching to medium settings or somehow removing fps limit) without stutters.
  I'm pretty new to arch and linux in general (and github sry)

Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-2957426376

I can confirm this has a significant performance improvement in multiplayer. However, I did notice that now I am prone to freezes or frame drops (Still much better experience than before tho). Freezes happen now at a similar rate to that of windows.

Edit: Changing the scheduler back to default (EEVDF) fixed all framedrop and freezes in the game too. So now I have perfectly stable performance with no freezes/lags or framedrops in multiplayer. It seems that both these solutions work well together. By default, on cachyos, it uses BORE scheduler, which I suspect is also causing problems.

While I can play with no issues, I'm getting this logs on launching the Game:

Using Proton Experimental (On regular branch)

Process 5508 (start_protected) of user 1000 dumped core.

                                                 Module /run/host/usr/lib/libicudata.so.76.1 without build-id.
                                                 Module /run/host/usr/lib/libicudata.so.76.1
                                                 Module /run/host/usr/lib/libicuuc.so.76.1 without build-id.
                                                 Module /run/host/usr/lib/libicuuc.so.76.1
                                                 Module /home/alosarjos/.local/share/Steam/steamapps/common/Proton - Experimental/files/lib/wine/x86_64-unix/dnsapi.so without build-id.
                                                 Module /home/alosarjos/.local/share/Steam/steamapps/common/Proton - Experimental/files/lib/wine/x86_64-unix/secur32.so without build-id.
                                                 Module /home/alosarjos/.local/share/Steam/steamapps/common/Proton - Experimental/files/lib/wine/x86_64-unix/winevulkan.so without build-id.
                                                 Module /home/alosarjos/.local/share/Steam/steamapps/common/Proton - Experimental/files/lib/wine/x86_64-unix/winex11.so without build-id.
                                                 Module /home/alosarjos/.local/share/Steam/steamapps/common/Proton - Experimental/files/lib/wine/x86_64-unix/bcrypt.so without build-id.
                                                 Module /home/alosarjos/.local/share/Steam/steamapps/common/Proton - Experimental/files/lib/wine/x86_64-unix/win32u.so without build-id.
                                                 Module /home/alosarjos/.local/share/Steam/steamapps/common/Proton - Experimental/files/lib/wine/x86_64-unix/crypt32.so without build-id.
                                                 Module /home/alosarjos/.local/share/Steam/steamapps/common/Proton - Experimental/files/lib/wine/x86_64-unix/ntdll.so without build-id.
                                                 Module /home/alosarjos/.local/share/Steam/steamapps/common/Proton - Experimental/files/lib/wine/x86_64-unix/ws2_32.so without build-id.
                                                 Module /home/alosarjos/.local/share/Steam/steamapps/common/Proton - Experimental/files/bin/wine64 without build-id.
                                                 Module /home/alosarjos/.local/share/Steam/steamapps/common/Proton - Experimental/files/bin/wine64-preloader without build-id.
                                                 Stack trace of thread 5567:
                                                 #0  0x00007f7573cf120a save_context (/home/alosarjos/.local/share/Steam/steamapps/common/Proton - Experimental/files/lib/wine/x86_64-unix/ntdll.so + 0x4a20a)
                                                 #1  0x00007f7573cf2f91 segv_handler (/home/alosarjos/.local/share/Steam/steamapps/common/Proton - Experimental/files/lib/wine/x86_64-unix/ntdll.so + 0x4bf91)
                                                 #2  0x00007f757568aef0 n/a (/run/host/usr/lib/libc.so.6 + 0x3def0)
                                                 #3  0x00007f7563de9284 n/a (n/a + 0x0)
                                                 #4  0x00007f75756e27eb n/a (/run/host/usr/lib/libc.so.6 + 0x957eb)
                                                 #5  0x00007f757576618c n/a (/run/host/usr/lib/libc.so.6 + 0x11918c)
                                                 ELF object binary architecture: AMD x86-64

Not sure if it was an update on Mesa, the kernel or the game with the new DLC. I started playing again after the DLC release and my framedrops have completely disappeared at least :D

The game runs perfectly fine in local/offline scenarios (e.g., in the training area or while idling in the lobby). However, the client crashes consistently the moment a multiplayer session is established. This occurs in both solo matchmaking and when inviting a friend; as soon as the lobby contains more than one player, the application terminates.

Inspecting dmesg reveals a flood of x86/split lock detection warnings triggered by nightreign.exe and NWMTSocketManag immediately preceding the crash. The kernel's mitigation overhead appears to be causing a timeout or fatal stall. Shortly after the split lock warnings begin, IPC:CSteamEngin crashes with a segfault in steamclient.so. I suspect the latency introduced by the kernel's split lock mitigation causes a race condition or timeout within steamclient.so, leading to the segfault.

Dec 27 00:10:40 steam[17860]: [2025-12-27 00:10:39] Background update loop checking for update. . .
Dec 27 00:10:40 steam[17860]: [2025-12-27 00:10:39] Checking for available updates...
Dec 27 00:10:40 steam[17860]: [2025-12-27 00:10:39] Downloading manifest: https://media.st.dl.eccdnx.com/client/steam_client_publicbeta_ubuntu12
Dec 27 00:10:40 steam[17860]: [2025-12-27 00:10:40] Manifest download: send request
Dec 27 00:10:40 steam[17860]: [2025-12-27 00:10:40] Manifest download: waiting for download to finish
Dec 27 00:10:40 steam[17860]: [2025-12-27 00:10:40] Manifest download: finished
Dec 27 00:10:40 steam[17860]: [2025-12-27 00:10:40] Download skipped by HTTP 304 Not Modified
Dec 27 00:10:40 steam[17860]: [2025-12-27 00:10:40] Nothing to do
Dec 27 00:11:04 steam[17860]: fsync: up and running.
Dec 27 00:11:08 steam[17860]: chdir "/home/<redacted>/.local/share/Steam/steamapps/common/ELDEN RING NIGHTREIGN/Game"
Dec 27 00:11:08 steam[17860]: Game Recording - would start recording game 2622380, but recording for this game is disabled
Dec 27 00:11:08 steam[17860]: Adding process 19045 for gameID 2622380
Dec 27 00:11:08 steam[17860]: ERROR: ld.so: object '/home/<redacted>/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Dec 27 00:11:08 steam[17860]: ERROR: ld.so: object '/home/<redacted>/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Dec 27 00:11:08 steam[17860]: ERROR: ld.so: object '/home/<redacted>/.local/share/Steam/ubuntu12_64/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS64): ignored.
Dec 27 00:11:08 steam[17860]: ERROR: ld.so: object '/home/<redacted>/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Dec 27 00:11:08 steam[17860]: ERROR: ld.so: object '/home/<redacted>/.local/share/Steam/ubuntu12_32/gameoverlayrenderer.so' from LD_PRELOAD cannot be preloaded (wrong ELF class: ELFCLASS32): ignored.
Dec 27 00:11:08 steam[17860]: Adding process 19046 for gameID 2622380
Dec 27 00:11:08 steam[17860]: Adding process 19047 for gameID 2622380
Dec 27 00:11:08 steam[17860]: Adding process 19132 for gameID 2622380
Dec 27 00:11:08 steam[17860]: fsync: up and running.
Dec 27 00:11:08 steam[17860]: Adding process 19133 for gameID 2622380
Dec 27 00:11:08 steam[17860]: Adding process 19134 for gameID 2622380
Dec 27 00:11:08 steam[17860]: Adding process 19135 for gameID 2622380
Dec 27 00:11:08 steam[17860]: Adding process 19138 for gameID 2622380
Dec 27 00:11:08 steam[17860]: Adding process 19140 for gameID 2622380
Dec 27 00:11:08 steam[17860]: Adding process 19143 for gameID 2622380
Dec 27 00:11:08 steam[17860]: Adding process 19152 for gameID 2622380
Dec 27 00:11:09 steam[17860]: Adding process 19157 for gameID 2622380
Dec 27 00:11:09 steam[17860]: Adding process 19164 for gameID 2622380
Dec 27 00:11:10 steam[17860]: Adding process 19188 for gameID 2622380
Dec 27 00:11:10 steam[17860]: Adding process 19205 for gameID 2622380
Dec 27 00:11:10 steam[17860]: Fossilize INFO: Overriding serialization path: "/home/<redacted>/.local/share/Steam/steamapps/shadercache/2622380/fozpipelinesv6/steamapprun_pipeline_cache".
Dec 27 00:11:11 steam[17860]: 12/27 00:11:11 minidumps folder is set to /tmp/dumps
Dec 27 00:11:11 steam[17860]: 12/27 00:11:11 Init: Installing breakpad exception handler for appid(gameoverlayui)/version(20251224182953)/tid(19268)
Dec 27 00:11:11 steam[17860]: 12/27 00:11:11 Init: Installing breakpad exception handler for appid(gameoverlayui)/version(1.0)/tid(19268)
Dec 27 00:11:12 kernel: x86/split lock detection: #AC: nightreign.exe/19272 took a split_lock trap at address: 0x7f124deccad6
Dec 27 00:11:14 kernel: x86/split lock detection: #AC: nightreign.exe/19274 took a split_lock trap at address: 0x7f124deccad6
Dec 27 00:11:15 kernel: x86/split lock detection: #AC: nightreign.exe/19276 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:16 steam[17860]: Adding process 19272 for gameID 2622380
Dec 27 00:11:17 steam[17860]: Setting breakpad minidump AppID = 2622380
Dec 27 00:11:17 steam[17860]: SteamInternal_SetMinidumpSteamID:  Caching Steam ID:  76561198323496050 [API loaded no]
Dec 27 00:11:17 kernel: x86/split lock detection: #AC: nightreign.exe/19281 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:17 kernel: x86/split lock detection: #AC: Core.Logging.Ba/19282 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:17 kernel: x86/split lock detection: #AC: DevConnect Syst/19283 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:17 kernel: x86/split lock detection: #AC: FD4JobWorker:0/19284 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:17 kernel: x86/split lock detection: #AC: FD4JobWorker:1/19285 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:17 kernel: x86/split lock detection: #AC: FD4JobWorker:2/19286 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:17 kernel: x86/split lock detection: #AC: FD4JobWorker:3/19287 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:17 kernel: split_lock_warn: 2 callbacks suppressed
Dec 27 00:11:17 kernel: x86/split lock detection: #AC: CSPlacementDebu/19291 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:17 kernel: x86/split lock detection: #AC: nightreign.exe/19292 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:18 kernel: x86/split lock detection: #AC: CSCheatDetectio/19295 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:18 kernel: x86/split lock detection: #AC: EWP_HIGHEST_Fix/19300 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:18 kernel: x86/split lock detection: #AC: EWP_HIGHEST_Fix/19301 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:18 kernel: x86/split lock detection: #AC: EWP_HIGHEST_Fix/19302 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:18 kernel: x86/split lock detection: #AC: EWP_HIGHEST_Fix/19303 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:18 kernel: x86/split lock detection: #AC: EWP_HIGHEST_Fix/19304 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:18 kernel: x86/split lock detection: #AC: EWP_HIGHEST_Fix/19305 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:18 kernel: x86/split lock detection: #AC: EWP_HIGHEST_Sin/19307 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:18 steam[17860]: 12/27 00:11:18 minidumps folder is set to /tmp/dumps
Dec 27 00:11:18 steam[17860]: 12/27 00:11:18 Init: Installing breakpad exception handler for appid(gameoverlayui)/version(20251224182953)/tid(19319)
Dec 27 00:11:18 steam[17860]: 12/27 00:11:18 Init: Installing breakpad exception handler for appid(gameoverlayui)/version(1.0)/tid(19319)
Dec 27 00:11:19 steam[17860]: Fossilize INFO: Overriding serialization path: "/home/<redacted>/.local/share/Steam/steamapps/shadercache/2622380/fozpipelinesv6/steamapprun_pipeline_cache".
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 minidumps folder is set to /tmp/dumps
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 Init: Installing breakpad exception handler for appid(gameoverlayui)/version(20251224182953)/tid(19404)
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 Init: Installing breakpad exception handler for appid(gameoverlayui)/version(1.0)/tid(19404)
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 minidumps folder is set to /tmp/dumps
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 Init: Installing breakpad exception handler for appid(gameoverlayui)/version(20251224182953)/tid(19406)
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 Init: Installing breakpad exception handler for appid(gameoverlayui)/version(1.0)/tid(19406)
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 minidumps folder is set to /tmp/dumps
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 Init: Installing breakpad exception handler for appid(gameoverlayui)/version(20251224182953)/tid(19407)
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 Init: Installing breakpad exception handler for appid(gameoverlayui)/version(1.0)/tid(19407)
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 minidumps folder is set to /tmp/dumps
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 Init: Installing breakpad exception handler for appid(gameoverlayui)/version(20251224182953)/tid(19408)
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 Init: Installing breakpad exception handler for appid(gameoverlayui)/version(1.0)/tid(19408)
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 minidumps folder is set to /tmp/dumps
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 Init: Installing breakpad exception handler for appid(gameoverlayui)/version(20251224182953)/tid(19409)
Dec 27 00:11:20 steam[17860]: 12/27 00:11:20 Init: Installing breakpad exception handler for appid(gameoverlayui)/version(1.0)/tid(19409)
Dec 27 00:11:24 steam[17860]: Fossilize WARN: Pipeline library handle 0x00007f1164d2ff60 is not registered.
Dec 27 00:11:24 steam[17860]: It has either not been recorded, or it failed to be recorded earlier (which is expected if application uses an extension that is not recognized by Fossilize).
Dec 27 00:11:24 steam[17860]: Fossilize WARN: Pipeline library handle 0x00007f11655e37e0 is not registered.
Dec 27 00:11:24 steam[17860]: It has either not been recorded, or it failed to be recorded earlier (which is expected if application uses an extension that is not recognized by Fossilize).
Dec 27 00:11:24 steam[17860]: Fossilize WARN: Pipeline library handle 0x00007f1166d5fdf0 is not registered.
Dec 27 00:11:24 steam[17860]: It has either not been recorded, or it failed to be recorded earlier (which is expected if application uses an extension that is not recognized by Fossilize).
Dec 27 00:11:24 kernel: split_lock_warn: 49 callbacks suppressed
Dec 27 00:11:24 kernel: x86/split lock detection: #AC: SLSession/19416 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:28 steam[17860]: reaping pid: 19268 -- gameoverlayui
Dec 27 00:11:33 kernel: x86/split lock detection: #AC: MovieSetup/19425 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:34 kernel: x86/split lock detection: #AC: MovieSetup/19427 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:34 kernel: x86/split lock detection: #AC: MovieSetup/19428 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:34 kernel: x86/split lock detection: #AC: MovieSetup/19429 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:34 kernel: x86/split lock detection: #AC: MovieSetup/19426 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:36 kdeconnectd[1409]: No uuids found for "10:48:B1:60:99:A9"
Dec 27 00:11:38 steam[17860]: reaping pid: 19404 -- gameoverlayui
Dec 27 00:11:38 kernel: x86/split lock detection: #AC: Bnd4FSAsync/19434 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:39 kernel: x86/split lock detection: #AC: Bnd4FSAsync/19435 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:39 kernel: x86/split lock detection: #AC: Bnd4FSAsync/19436 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:39 kernel: x86/split lock detection: #AC: Bnd4FSAsync/19437 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:40 kernel: x86/split lock detection: #AC: NWMTSocketManag/19438 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:41 kernel: x86/split lock detection: #AC: nightreign.exe/19415 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:42 kernel: x86/split lock detection: #AC: wine_threadpool/19439 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:44 kernel: x86/split lock detection: #AC: nightreign.exe/19277 took a split_lock trap at address: 0x7f124dec9fb3
Dec 27 00:11:45 kernel: x86/split lock detection: #AC: LibwebsocketsTh/19293 took a split_lock trap at address: 0x7f124dec1e5d
Dec 27 00:11:45 kernel: x86/split lock detection: #AC: nightreign.exe/19444 took a split_lock trap at address: 0x7f124dec33fa
Dec 27 00:11:48 steam[17860]: reaping pid: 19406 -- gameoverlayui
Dec 27 00:11:52 kernel: x86/split lock detection: #AC: Bnd4FSAsync/19446 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:54 kernel: x86/split lock detection: #AC: CSChrBackInitia/19449 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:54 kernel: x86/split lock detection: #AC: WorldShift1/19450 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:54 kernel: x86/split lock detection: #AC: WorldShift2/19451 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:54 kernel: x86/split lock detection: #AC: WorldShift3/19452 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:54 kernel: x86/split lock detection: #AC: WorldShift4/19453 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:54 kernel: x86/split lock detection: #AC: WorldShift5/19454 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:54 kernel: x86/split lock detection: #AC: HkAiThread1/19455 took a split_lock trap at address: 0x7f124dece00c
Dec 27 00:11:58 steam[17860]: reaping pid: 19407 -- gameoverlayui
Dec 27 00:11:59 kernel: x86/split lock detection: #AC: nightreign.exe/19275 took a split_lock trap at address: 0x7f124dec738d
Dec 27 00:12:08 steam[17860]: reaping pid: 19408 -- gameoverlayui
Dec 27 00:12:18 steam[17860]: reaping pid: 19409 -- gameoverlayui
Dec 27 00:12:36 kdeconnectd[1409]: No uuids found for "10:48:B1:60:99:A9"
Dec 27 00:12:51 kernel: x86/split lock detection: #AC: nightreign.exe/19466 took a split_lock trap at address: 0x7f124dec33fa
Dec 27 00:13:36 kdeconnectd[1409]: No uuids found for "10:48:B1:60:99:A9"
Dec 27 00:14:36 kdeconnectd[1409]: No uuids found for "10:48:B1:60:99:A9"
Dec 27 00:14:42 kernel: x86/split lock detection: #AC: nightreign.exe/19478 took a split_lock trap at address: 0x7f124dec33fa
Dec 27 00:15:08 steam[17860]: crash_20251227001508_39.dmp[19484]: Uploading dump (out-of-process)
Dec 27 00:15:08 steam[17860]: /tmp/dumps/crash_20251227001508_39.dmp
Dec 27 00:15:08 crash_20251227001508_39.dmp[19484]: Uploading dump (out-of-process)
                                                    /tmp/dumps/crash_20251227001508_39.dmp
Dec 27 00:15:08 kernel: IPC:CSteamEngin[19464]: segfault at c44fe116 ip 00000000dc49bcb7 sp 00000000d87fd7c0 error 4 in steamclient.so[258acb7,dacd4000+1eba000] likely on CPU 15 (core 27, socket 0)
Dec 27 00:15:08 kernel: Code: 00 00 00 8d bd 14 ff ff ff eb 27 8d b4 26 00 00 00 00 90 8b 50 08 8b 18 83 ec 08 89 bd f8 fe ff ff 8b 02 ff b5 ec fe ff ff 52 <ff> 50 04 83 c4 10 89 d8 39 c6 75 dd 8b b5 1c ff ff ff 8d 85 14 ff
Dec 27 00:15:08 systemd-coredump[19485]: Process 17956 (steam) of user 1000 terminated abnormally with signal 11/SEGV, processing...
Dec 27 00:15:08 systemd[1]: Started Process Core Dump (PID 19485/UID 0).
Dec 27 00:15:09 systemd-coredump[19487]: [🡕] Process 17956 (steam) of user 1000 dumped core.

                                         Stack trace of thread 19464:
                                         #0  0x00000000dc49bcb7 n/a (steamclient.so + 0x258bcb7)
                                         #1  0x00000000dc49c7ba n/a (steamclient.so + 0x258c7ba)
                                         #2  0x00000000dc4847d6 n/a (steamclient.so + 0x25747d6)
                                         #3  0x00000000dc488a66 n/a (steamclient.so + 0x2578a66)
                                         #4  0x00000000dc40acde n/a (steamclient.so + 0x24facde)
                                         #5  0x00000000dc40c162 n/a (steamclient.so + 0x24fc162)
                                         #6  0x00000000f7cada8b n/a (libc.so.6 + 0x93a8b)
                                         #7  0x00000000f7d49548 n/a (libc.so.6 + 0x12f548)

                                         Stack trace of thread 18043:
                                         #0  0x00000000f7cb6a9b n/a (libc.so.6 + 0x9ca9b)
                                         #1  0x00000000f7ca9a40 n/a (libc.so.6 + 0x8fa40)
                                         #2  0x00000000f7ca9ae9 n/a (libc.so.6 + 0x8fae9)
                                         #3  0x00000000f7d49a85 epoll_wait (libc.so.6 + 0x12fa85)
                                         #4  0x00000000e40ffbf7 n/a (steamservice.so + 0x262bf7)
                                         #5  0x00000000e41004b1 n/a (steamservice.so + 0x2634b1)
                                         #6  0x00000000e44246ee n/a (steamservice.so + 0x5876ee)
                                         #7  0x00000000e44214b8 n/a (steamservice.so + 0x5844b8)
                                         #8  0x00000000e4421dff n/a (steamservice.so + 0x584dff)
                                         #9  0x00000000e44284d4 n/a (steamservice.so + 0x58b4d4)
                                         [#10](/issue/ValveSoftware/Proton/10) 0x00000000f7cada8b n/a (libc.so.6 + 0x93a8b)
                                         [#11](/issue/ValveSoftware/Proton/11) 0x00000000f7d49548 n/a (libc.so.6 + 0x12f548)

                                         Stack trace of thread 17960:
                                         #0  0x00000000f7cb6a9b n/a (libc.so.6 + 0x9ca9b)
                                         #1  0x00000000f7ca9a40 n/a (libc.so.6 + 0x8fa40)
                                         #2  0x00000000f7caa1f8 n/a (libc.so.6 + 0x901f8)
                                         #3  0x00000000f7cad388 __pthread_cond_timedwait64 (libc.so.6 + 0x93388)
                                         #4  0x00000000f7cad463 pthread_cond_timedwait (libc.so.6 + 0x93463)
                                         #5  0x00000000568dea75 n/a (/home/<redacted>/.local/share/Steam/ubuntu12_32/steam + 0x2dea75)
                                         #6  0x0000000056d46f14 n/a (/home/<redacted>/.local/share/Steam/ubuntu12_32/steam + 0x746f14)
                                         #7  0x00000000568de78e n/a (/home/<redacted>/.local/share/Steam/ubuntu12_32/steam + 0x2de78e)
                                         #8  0x00000000568db558 n/a (/home/<redacted>/.local/share/Steam/ubuntu12_32/steam + 0x2db558)
                                         #9  0x00000000568dbe9f n/a (/home/<redacted>/.local/share/Steam/ubuntu12_32/steam + 0x2dbe9f)
                                         [#10](/issue/ValveSoftware/Proton/10) 0x00000000568e2574 n/a (/home/<redacted>/.local/share/Steam/ubuntu12_32/steam + 0x2e2574)
                                         [#11](/issue/ValveSoftware/Proton/11) 0x00000000f7cada8b n/a (libc.so.6 + 0x93a8b)
                                         [#12](/issue/ValveSoftware/Proton/12) 0x00000000f7d49548 n/a (libc.so.6 + 0x12f548)

                                         Stack trace of thread 17967:
                                         #0  0x00000000f7cb6a9b n/a (libc.so.6 + 0x9ca9b)
                                         #1  0x00000000f7ca9a40 n/a (libc.so.6 + 0x8fa40)
                                         #2  0x00000000f7caa1f8 n/a (libc.so.6 + 0x901f8)
                                         #3  0x00000000f7cad179 pthread_cond_wait (libc.so.6 + 0x93179)
                                         #4  0x00000000f3b0c4d8 _ZN16SteamThreadTools17CThreadSyncObject4WaitEj (libtier0_s.so + 0x354d8)
                                         #5  0x00000000f542425c n/a (steamui.so + 0x18ef25c)
                                         #6  0x00000000f3b0a50e _ZN16SteamThreadTools7CThread22ThreadExceptionWrapperEPv (libtier0_s.so + 0x3350e)
                                         #7  0x00000000f3b07cae n/a (libtier0_s.so + 0x30cae)
                                         #8  0x00000000f3b08570 CatchAndWriteMiniDumpExForVoidPtrFn (libtier0_s.so + 0x31570)
                                         #9  0x00000000f3b085b8 CatchAndWriteMiniDumpForVoidPtrFn (libtier0_s.so + 0x315b8)
                                         [#10](/issue/ValveSoftware/Proton/10) 0x00000000f3b0d362 _ZN16SteamThreadTools7CThread10ThreadProcEPv (libtier0_s.so + 0x36362)
                                         [#11](/issue/ValveSoftware/Proton/11) 0x00000000f7cada8b n/a (libc.so.6 + 0x93a8b)
                                         [#12](/issue/ValveSoftware/Proton/12) 0x00000000f7d49548 n/a (libc.so.6 + 0x12f548)

                                         Stack trace of thread 17956:
                                         #0  0x00000000f7cb6a9b n/a (libc.so.6 + 0x9ca9b)
                                         #1  0x00000000f7ca9a40 n/a (libc.so.6 + 0x8fa40)
                                         #2  0x00000000f7ca9ae9 n/a (libc.so.6 + 0x8fae9)
                                         #3  0x00000000f7d3c393 __poll (libc.so.6 + 0x122393)
                                         #4  0x00000000efc4cb53 n/a (vgui2_s.so + 0x14cb53)
                                         #5  0x00000000efc58d6c n/a (vgui2_s.so + 0x158d6c)
                                         #6  0x00000000f50e05ae n/a (steamui.so + 0x15ab5ae)
                                         #7  0x00000000f50e2a88 n/a (steamui.so + 0x15ada88)
                                         #8  0x00000000f50e49a4 n/a (steamui.so + 0x15af9a4)
                                         #9  0x000000005689e46d n/a (/home/<redacted>/.local/share/Steam/ubuntu12_32/steam + 0x29e46d)
                                         [#10](/issue/ValveSoftware/Proton/10) 0x000000005689f6e0 n/a (/home/<redacted>/.local/share/Steam/ubuntu12_32/steam + 0x29f6e0)
                                         [#11](/issue/ValveSoftware/Proton/11) 0x00000000568a0615 n/a (/home/<redacted>/.local/share/Steam/ubuntu12_32/steam + 0x2a0615)
                                         [#12](/issue/ValveSoftware/Proton/12) 0x00000000f7c3c535 n/a (libc.so.6 + 0x22535)
                                         [#13](/issue/ValveSoftware/Proton/13) 0x00000000f7c3c60e __libc_start_main (libc.so.6 + 0x2260e)
                                         [#14](/issue/ValveSoftware/Proton/14) 0x0000000056884031 n/a (/home/<redacted>/.local/share/Steam/ubuntu12_32/steam + 0x284031)
                                         ELF object binary architecture: Intel 80386
Dec 27 00:15:09 systemd[1]: systemd-coredump@7-28673-19485_19486-0.service: Deactivated successfully.
Dec 27 00:15:09 systemd[1]: systemd-coredump@7-28673-19485_19486-0.service: Consumed 1.085s CPU time over 1.124s wall clock time, 546.1M memory peak.
Dec 27 00:15:09 steam[17860]: /home/<redacted>/.local/share/Steam/steam.sh: line 928: 17956 Segmentation fault         (core dumped) "$STEAMROOT/$STEAMEXEPATH" "$@"

Echoing @Avimitin , I am seeing a similar condition causing crashes on any networking. I can't attach the whole log due to size constraints, but I have the proton log available if it is wanted.

3749.509:01f8:0228:trace:seh:RtlRestoreContext returning to 000000014167587C stack 000000000311FAD0
src/common/pipes.cpp (900) : fatal stalled cross-thread pipe.
src/common/pipes.cpp (900) : Fatal assert; application exiting
12/26 23:07:50 minidumps folder is set to /tmp/dumps
assert_20251226230750_3.dmp[28850]: Uploading dump (out-of-process)
/tmp/dumps/assert_20251226230750_3.dmp
assert_20251226230750_3.dmp[28850]: Finished uploading minidump (out-of-process): success = yes
assert_20251226230750_3.dmp[28850]: response: Discarded=1
assert_20251226230750_3.dmp[28850]: file ''/tmp/dumps/assert_20251226230750_3.dmp'', upload yes: ''Discarded=1''
3930.378:0100:0438:warn:threadname:NtSetInformationThread Thread renamed to L"wine_threadpool_worker"
3930.424:0130:0180:trace:unwind:RtlGrowFunctionTable 0000000000D29CD0, 75
3930.424:0130:043c:trace:mscoree:DllMain (00006FFFFDD80000, 2, 0000000000000000)
3930.425:0130:0160:warn:seh:dispatch_exception backtrace: --- Exception 0x6be.
3930.425:0130:0160:trace:seh:dispatch_exception code=6be (unknown) flags=0 addr=00006FFFFFC0D217
3930.425:0130:0160:trace:seh:dispatch_exception rip=00006fffffc0d217 rsp=0000000003c9e400 rbp=0000000003c9e4f0 eflags=00000206
3930.425:0130:0160:trace:seh:dispatch_exception rax=0000000003c9e420 rbx=0000000003c9f2a0 rcx=0000000003c9e420 rdx=0000000000000000
3930.425:0130:0160:trace:seh:dispatch_exception rsi=0000000000000014 rdi=0000000000000000  r8=0000000000000000  r9=0000000000000000
3930.425:0130:0160:trace:seh:dispatch_exception r10=000000000065b7c0 r11=0000000000000014 r12=0000000003c9e5a8 r13=0000000000000005
3930.425:0130:0160:trace:seh:dispatch_exception r14=00006fffffa8d260 r15=00006fffff932ee2 mxcsr=00001f80
3930.425:0130:0160:trace:seh:call_vectored_handlers calling handler at 00006FFFFD7F05F0 code=6be flags=0

Issue fix after I switch back to Steam stable version. And I remember that my steam deck works in former Steam Experiment version. Maybe the recent Experiment update breaks the game.

I've tried various revisions without success. Still trying out things, but its been the same behavior on all.

@zphensley42 are you using steam client beta? try switching back to stable

I was on stable. I spent some time moving away from my kernel this morning and no longer have issues with proton on nobara this morning.

I've noticed when I run this with PROTON_ENABLE_WAYLAND I cannot get the game to accept input via gamepad. Is there any way around this?

@StelardActek Game depends on steam input, steam input depends on steam overlay, overlay depends on X. So the fix is on valve time unfortunately.

I've noticed when I run this with PROTON_ENABLE_WAYLAND I cannot get the game to accept input via gamepad. Is there any way around this?

You can modify Steam's desktop file or launch it from your command line with steam -steamos while having PROTON_ENABLE_WAYLAND activated. This allows Steam Input to work under Wayland. I've been using it for months.

If you have it automatically login to and open the friends list under XWayland and wish to replicate this, you have to run it as steam -steamos +open steam://open/friends because, naturally, the Steam Deck (SteamOS) does not open the friends list when Steam starts.

You can modify Steam's desktop file or launch it from your command line with steam -steamos while having PROTON_ENABLE_WAYLAND activated. This allows Steam Input to work under Wayland. I've been using it for months.

If you have it automatically login to and open the friends list under XWayland and wish to replicate this, you have to run it as steam -steamos +open steam://open/friends because, naturally, the Steam Deck (SteamOS) does not open the friends list when Steam starts.

This works perfectly for me! Thanks for including the friend list part, I do want that.

I'm getting this weird problem where once per play session, I'll get massive slow down (15fps) for about 5-10 seconds within the first 1-3 minutes of an expedition:

https://github.com/user-attachments/assets/9eadfee0-2736-418f-9bf2-a52c8cd20db5

https://github.com/user-attachments/assets/b93079ca-3aae-4e58-9b7b-a6028d782055

It happens even with all graphical settings set to Low, solo or multiplayer. I've tried X11 Xfce and KDE Plasma Wayland. It's just once per gameplay session, even if I play for 3 hours straight I'll only get it once at the beginning. If I restart the game it'll come back though. I can't seem to reproduce it on the steamdeck either.

Hardware:
OS: Arch Linux
GPU: Sapphire pulse RX 6700 XT
CPU: Ryzen 3700X
32G RAM

The game otherwise runs great throughout. Anyone else getting this problem?

Replying to https://github.com/ValveSoftware/Proton/issues/8751#issuecomment-3941610908

Ever since the 64-bit client dropped, both the -steamos and -steamos3 args no longer work for me. :(

@jazztickets the slowdown issue may have been mitigated by the most recent game update, which appears to have updated some of the EAC/EOS files. I didn't encounter it during my sessions today, in any case.

@jazztickets the slowdown issue may have been mitigated by the most recent game update, which appears to have updated some of the EAC/EOS files. I didn't encounter it during my sessions today, in any case.

Nice! I did two full single-player rounds, one with Proton Experimental and one with Proton 10.0-4. Didn't experience the slowdown either time.