Compatibility Report

• Name of the game with compatibility issues:
  Gray Zone Warfare

• Steam AppID of the game:
  2479810

System Information

• GPU:
  NVIDIA GeForce RTX 5070 Ti (ASUS TUF Gaming OC, 16 GB GDDR7)

• Driver/LLVM version:
  NVIDIA 590.48.01

• Kernel version:
  Linux 6.18.2-1-cachyos-bore

• Link to full system information report as Gist:
  https://gist.github.com/xEnSei/1d154ce9fdc546d7975fc564bddc5f08

• Proton version:
  Proton 10.0-3
  (Issue also reproducible on Proton Experimental)

I confirm:

• [✓] that I haven't found an existing compatibility report describing this exact issue in sufficient detail
• [✓] that I have checked whether there are updates for my system available

Symptoms

The video shows the current problem:
https://www.youtube.com/watch?v=1hqUNFOmgZ8

Summary

Severe performance degradation and system-wide stalls when loading into a server.
The game becomes temporarily unresponsive and can freeze the entire desktop environment.

Detailed behavior

• Game launches normally and reaches main menu without issues
• When joining a server, loading freezes consistently around 70–75 %
• During this phase:
  • CPU usage spikes to 100 % across all cores
  • GPU usage drops to near idle
  • Desktop, audio and input lag system-wide
• After several time:
  • Either the game recovers
  • Or crashes

Important observations

• The issue only affects Gray Zone Warfare
• Other UE5 titles run fine under Proton on the same system
• Windows does not show this behavior on identical hardware
• The problem started with GZW patch 0.3.5.0

Temporary workaround

Limiting the visible CPU topology significantly improves behavior:

WINE_CPU_TOPOLOGY=12:1,2,3,4,5,6,7,8,9,10,11,12

Reproduction

Start the Game -> Join the Server -> watch the problem

System Information
https://gist.github.com/xEnSei/8cdd84c1704d5c8afd43561ffd310ea2

Steam Runtime Diagnostics
https://gist.github.com/xEnSei/c133f85a137456be1cea5d7ea9842691

steam-2479810.log

The video shows the problem, but here “GE-Proton10-28” is used, so the difference is that the game doesn't crash but has the same performance issues.
https://www.youtube.com/watch?v=1hqUNFOmgZ8