protonscr

100% CPU / core lock-up on start

steamclosed
ValveSoftware/steam-for-linux#13455 · opened 2026-07-27 by dcog989 · updated 2026-07-27 · 2 comments · github
Ddcog989 2026-07-27 github
  • Steam client version (build number or date): 1784778118
  • Distribution (e.g. Ubuntu): CachyOS
  • Opted into Steam client beta?: No
  • Have you checked for system updates?: Yes
  • Steam Logs: attached
  • GPU: AMD

On startup, Steam usually but not always consumes 100% CPU on one core, showing a single 'steamwebhelper' as the culprit.

Image

it will cause terrible in-game performance if i do not 'fix' it by randomly interacting with the Steam app (usually I open Settings > Downloads then close Settings) which usually stops the core lock-up, although sometimes I restart the Steam app which might fix it, but I cannot see a clear pattern.

this has been ongoing for many months, not certain of exact start point.

steam-logs.tar.gz

Kkisak-valve maintainer 2026-07-27 github

Hello @dcog989, --disable-gpu-compositing --disable-gpu in your webhelper.txt and Disabling GPU acceleration: Disabled/CommandLine in your webhelper_gpu.txt log tells us that Steam's web component is configured to render on the CPU. That configuration using CPU resources to run is not a bug by itself and you can control it in Steam's settings at Steam -> Settings -> Interface -> toggle Enable GPU accelerated rendering in web views (requires restart)

Alternatively, you can look in the Library section of Steam's settings for a couple settings that can lighten the rendering load.

Ddcog989 2026-07-27 github

Hi @kisak-valve, thanks for the quick reply.

I switched to GPU rendering + switched on the 'low effort' options in Library section - now I see high (not 100%) CPU and prolonged high GPU on startup. This lasts ~1 minute then drops back to ~zero idle.

So, kind of fixed, but it still seems like an excessive amount of resources being chewed up on startup (I only have one game installed). Hopefully, some optimisations can be found.

Thanks again.

Nothing extracted yet.