Proton 9.0-4 is out now bringing big compatibility improvements for Steam Deck / Linux

The latest stable version of the compatibility layer to run Windows games on Steam Deck / Desktop Linux from Valve, Proton 9.0-4 is out now.

Bringing with it a whole lot of changes that were previously only available via Proton Experimental and Proton Hotfix, this will be the main version of Proton to use unless you need something specific from the likes of Proton Experimental. Confused? See my beginner's guide article.

One of the big new features in this release is the addition of support for the NVIDIA Optical Flow API and DLSS 3 Frame Generation for Desktop Linux. So NVIDIA GPU owners can now make use of it.

Plus for the Proton 9.0-4 release these are noted as newly playable:

• APB Reloaded
• Conqueror's Blade
• Cube Hero Odyssey
• Disgaea 4 Complete+
• Hard Chip Demo
• ScarQuest
• Sniper Elite: Nazi Zombie Army 2 (AMD GPUs only)
• Test Drive Unlimited Solar Crown
• Total War: SHOGUN 2
• Warhammer 40k: Space Marine 2 (requires disabled Steam Overlay)
• Welcome to Dustown

Pictured - Warhammer 40k: Space Marine 2

As for other improvements Valve continue making use of the open source Xalia tool to bring gamepad support to more launchers and game setup screens. This has now been enabled for Trackmania United Forever, Trackmania Nations Forever, Oddworld: Stranger's Wrath HD, Fallout: New Vegas, and WARRIORS ALL-STARS. Plus they've enabled it for the prerequisite installation for MultiVersus.

On top of that there's all these other fixes and improvements:

• Fixed Hell Let Loose crashing when joining a server after a recent game update.
• Fixed Final Fantasy XVI having low FPS due to excessive DLL lookup.
• Fixed Final Fantasy XVI not showing displays in settings.
• Fixed keyboard input in Rivals of Aether II.
• Fixed Chromacell crashing on launch on AMD GPUs.
• Fixed Dragon Age: The Veilguard displaying a warning about being installed on a spinning drive.
• Fixed Crazy Taxi randomly crashing when starting a game.
• Added a warning in Proton logs when running on system with low max_map_count.
• Fixed single player game not working in Star Wars - Jedi Knight II: Jedi Outcast.
• Fixed Hard Reset Redux and Shadow Warrior crashing with AMD GPUs.
• Fixed Skull and Bones not exiting cleanly on systems with Nvidia GPUs.
• Fixed Dark and Darker not being playable after a game update.
• Fixed EA Desktop App setup not being configurable.
• Improved video playback in March of Empires and Devil May Cry 3 Special Edition.
• Fixed trigger buttons not registering in I Expect You To Die.
• Fixed Proton 9.0 regressions:
  • Multiplayer works again in Hotshot Racing.
  • Fablecraft is playable again.
  • I Expect You To Die is playable again.
  • Star Wars: Knights of the Old Republic no longer launches to a black screen when in fullscreen mode.
  • Marlow Briggs and the Mask of Death is playable again.
  • B-17 Flying Fortress - The Mighty 8th: Redux is playable again.
  • Games now launch on the correct screen on setups with multiple monitors connected to multiple GPUs.
• Fixed Yakuza 3 Remastered and Yakuza 4 Remastered not being playable on some setups.
• Fixed Yakuza 6 crash when trying playing Puyo Puyo mini-game.
• Fixed Knowledge, or know Lady crashing about 10 minutes after launch.
• Fixed multiplayer in SpellForce 3: Versus Edition.
• Fixed font rendering in SpellForce 3: Versus Edition.
• Fixed mod support in DOOM Eternal.
• Fixed Mary Skelter 2 stuttering on launch.
• Fixed The Finals not starting with non-English locale.
• Fixed Traditional Chinese font rendering in Mashiroiro Symphony HD -Sana Edition-.
• Fixed Korean input in Diablo IV.
• Fixed newer Unreal Engine games trying to install redistributables on each launch.
• Fixed Astral Ascent hanging when unplugging a controller.
• Fixed playback of videos in Max: The Curse of Brotherhood.
• Fixed controller support in Clash for Crust.
• Fixed FPS drops in Red Dead Redemption 2 when keys are pressed.
• Fixed Hunt: Showdown 1896 failing to start after a recent game update.
• Fixed full screen in Dog Brew on Steam Deck.
• Fixed support for BattleServer in Age of Empires II: Definitive Edition.
• Fixed voice chat in For Honor and UNO.
• Fixed Proton not setting priorities correctly for new threads.
• Fixed Unreal Engine Crash Report Client not launching properly.
• Improved loading times in Pharaoh Rebirth+.
• Fixed missing icons in Age of Mythology: Retold.
• Fixed video playback in March of Empires.
• Improved performance in Blood Strike.
• Updated Wine Mono to 9.3.1.
• Updated dxvk to v2.5.1 + a regression fix.
• Updated dxvk-nvapi to v0.7.1-94-gafb59a8e841b.
• Updated vkd3d-proton to v2.13-241-g4fd7d3ab3d35.
• Updated vkd3d-shader to vkd3d-1.14 + a hack.

See all in the changelog.

It will just show up in your Steam Downloads as an update for Proton 9. Example from a Steam Deck:

That's if you already have it installed, which you likely do. Otherwise just search for Proton 9 directly in your Steam Library.

Don't forget there's also the recent Proton Experimental update that makes modding a whole lot easier, and brings with it initial speech synthesis support.