SteamOS & Proton Watch: SteamOS 3.9.3 Beta, a Faster Steam, and an ARC Raiders Fix

There’s been a lot of Valve activity in the last 48 hours. Here’s what’s new for SteamOS and Proton.

SteamOS 3.9.3 Beta

Valve posted SteamOS 3.9.3 Beta on October 16 for the Beta and Preview channels. You can opt in under Settings > System > System Update Channel. Valve’s notes say they contain “all changes since the current stable SteamOS 3.8 release.” Stable is still 3.8.

New in 3.9.3:

• Fixed performance issues in STAR WARS: Galactic Racer when resuming from suspend on Steam Machine.
• Fixed possible GPU errors in The Crew Motorfest.
• Fixed audio issues when hotplugging certain monitors in a multi-monitor setup.
• Improved support for the Steam Frame wireless adapter.
• Developer: reintroduced support for Android binder IPC.

What SteamOS 3.9 brings compared to 3.8:

• Desktop Mode moves from Plasma 6.4.3 to Plasma 6.7.3, on an updated Arch Linux base.
• The Linux kernel is rebased on Linux 7.2.
• Wi-Fi: new installs now use the wpa_supplicant backend by default, which now supports fast reconnect after sleep. Valve notes that existing installs stay on iwd unless you switch in Developer Settings.
• Hibernation: preliminary support, not yet shown in the Game Mode UI.
• Frame limiter fixes: “Disable Frame Limiter” now works with VRR, frame limits no longer give lower-than-intended FPS on some external displays, and the limiter no longer applies to VR titles streamed from Steam Machine to Steam Frame.
• Other fixes:
  • Suspend/resume on RDNA1 and RDNA2 dedicated GPUs.
  • Hidden Wi-Fi networks connecting on the first try.
  • Lost input after dragging a launcher window in Game Mode.
  • Remote Play on Steam Machine with no display connected.
• Hardware fixes:
  • Legion Go 2: fixed a crash launching Forza Horizon 6 and added preliminary brightness control.
  • ASUS: a workaround for high fan speed after sleep on some devices.
  • Intel: fixes for Panther Lake (ELDEN RING and DARK SOULS III failing to run) and Intel PTL+ boot screen corruption.

For my original Legion Go: it isn’t named anywhere in the 3.9 notes. Only the Legion Go 2 is. The general fixes may still apply, but nothing is specifically promised for the original.

Steam client beta, October 16: faster startup again

Valve’s October 16 Steam client beta adds a “second round of Steam startup performance improvements following shipping of prior improvements in public client.” GamingOnLinux says that in its own testing, Steam “really does load up ridiculously fast now.” That’s a hands-on impression, not a benchmark. Also in this beta:

• Linux: fixed Vulkan games hanging after alt-tab, and some native non-Steam games failing to launch.
• Fixed Steam Frame native-only content showing as installable on Windows.
• Voice chat output volume for friends now persists between sessions.
• Another British Columbia date fix.
• Steam Input now applies NCAA Football 27’s configuration correctly at startup.

This follows the October 15 beta that moved the Linux client to 64-bit and added Achievement Sets, which I covered in my separate Steam Linux 64-bit article.

Proton Experimental: ARC Raiders and more

GamingOnLinux reports that the October 15 Proton Experimental update:

• Fixed a rare crash in ARC Raiders.
• Fixed a crash regression in C&C Red Alert: Counterstrike and The Aftermath.
• Fixed a controller hotplug regression in Chrono Trigger.
• Made Breadbox playable.

Proton 11.0-3 is still a Release Candidate (opt-in on Proton 11). The current stable version is Proton 11.0-2.

Valve fixes STAR WARS Zero Company with a launch option

After Zero Company’s big 1.2 update, the game was crashing on Steam Machine. Valve’s Pierre-Loup Griffais said on Bluesky that “a fix has been deployed for Zero Company crashing on Steam Machine and will be automatically applied upon restarting the system.”

GamingOnLinux’s inference: after “doing a bit of investigating,” GamingOnLinux says Valve changed the game’s default launch options to disable NVIDIA NVAPI. Valve’s post doesn’t describe how the fix works. This fits with recent Proton changes that disable nvapi when no NVIDIA driver is present.

No new stable releases

Today there’s no new SteamOS stable or Proton stable release.

My take

Opinion: Plasma 6.7 and Linux 7.2 make 3.9 a big update for desktop mode. If you’re on a Legion Go like me, I’d wait for testers’ reports before switching to the beta channel.

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Sources

• Valve, Steam Deck News (SteamOS 3.9.3 Beta, Oct 16, 2026): https://www.steamdeck.com/en/news/
• GamingOnLinux, “SteamOS 3.9.3 Beta arrives with improved support for Steam Frame wireless adapter”: https://www.gamingonlinux.com/2026/10/steamos-3-9-3-beta-arrives-with-improved-support-for-steam-frame-wireless-adapter/
• GamingOnLinux, “Steam Client Beta for October 16 brings another round of startup performance improvements”: https://www.gamingonlinux.com/2026/10/steam-client-beta-for-october-16-brings-another-round-of-startup-performance-improvements/
• GamingOnLinux, “Proton Experimental for October 15 has fixes for ARC Raiders, C&C Red Alert, Counterstrike and The Aftermath”: https://www.gamingonlinux.com/2026/10/proton-experimental-for-october-15-has-fixes-for-arc-raiders-c-c-red-alert-counterstike-and-the-aftermath/
• GamingOnLinux, “Valve fix Zero Company crashing on Steam Machine with the latest major game update”: https://www.gamingonlinux.com/2026/10/valve-fix-zero-company-crashing-on-steam-machine-with-the-latest-major-game-update/
• Proton Changelog (GitHub wiki): https://github.com/ValveSoftware/Proton/wiki/Changelog