Valve Releases Proton 6.3-6, Improving Compatibility

Last night, Proton — the compatibility layer that allows Windows games to be played on Linux — was updated by Valve from 6.3-5 to 6.3-6. While the number scheming here may not sound like a big difference, according to the changelog there actually is quite a few remarkable improvements from 6.3-5. Specifically, we’re looking at more games being compatible with Proton, improved audio and video playback in a few titles, improved launcher behavior with one title, better input handling with others, upgrades of wine-monoDXVKvkd3d-proton, and FAudio, various game fixes, and better cloud sync behavior with a few titles.

Phew, that’s a lot to cover in a nutshell. Let’s break this up into byte-sized chunks. So for games that now work through Proton, they are:

  • Tokyo Xanadu eX+
  • Sonic Adventure 2
  • Rez Infinite
  • Elite Dangerous
  • Blood of Steel
  • Homeworld Remastered Collection
  • Star Wars Knights of the Old Republic
  • Guardians VR
  • 3D Aim Trainer

wine-mono was upgraded to 6.3.0 — nothing as far as specific games improvements with this release, but there seems to be quite a few bug fixes. DXVK upgraded from 1.9 to 1.9.1 — a few “performance and stability issues” were fixed from the D3D9 locking rewrite, workarounds for Mesa drivers 19.0 and below were removed, and a few games saw some crash fixes or better graphics quality, particularly those with NVIDIA GPUs. Games that are improved with DXVK 1.9.1 include Earth Defense Force 5Far Cry 1 and 5GTA IVRisen 3, and World of Final Fantasy.

As we noted a little over a month ago, vkd3d-proton 2.4 saw a GPU framerate increase in many titles; most noteworthy was Horizon Zero Dawn with a 15-20% FPS increase. Other titles improved by 5-10%. 2.4 also brought quite a few bug fixes, particularly for games like Cyberpunk 2077 and DIRT 5. Finally, FAudio was upgraded to 21.08 (there may be a typo on Valve’s part on the changelog; they wrote 20.08 while the link directs to 21.08) — though this upgrade seems to be pretty minor, it brought a few fixes, support for WaveBank entry names, and supports 5.1->5.1 processing.

Video playback has been improved: Deep Rock GalaticThe Medium, Nier: Replicant, and Contra: Rogue Corps benefit from this. Deep Rock Galatic, in addition to Fallout: New VegasOblivion, and Borderlands 3, also benefit from audio playback fixes.

For those whose mother tongue isn’t English, there’s a benefit here for you as well. Cyperpunk 2077 and the Rockstar Game launcher — the “non-English experience” has been improved (probably better support for non-ASCII characters?). Speaking of launchers, the launcher behavior for Swords of Legends Online has been improved.

For those with NVIDIA GPUs who want to use the company’s NVAPI support library and DLSS, this can be enabled by simply using the launch parameter PROTON_ENABLE_NVAPI=1. For those unaware of what DLSS (Deep Learning Super Sampling) is, this is the definition according to NVIDIA:

DLSS is a deep learning neural network that uses the power of the NVIDIA RTX TensorCores to boost frame rates and generate sharp frames that approach or exceed native rendering.

Beware, however, that only those with an RTX GPU will be able to benefit from DLSS – and you will also need to have the 470.x drivers at least from Nvidia. As for NVAPI, this is more so a developer feature that us end users don’t need to worry about too much, but for developers it will allow them to incorporate more features to enable better Proton compatibility with Windows games.

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Besides a few bug fixes and input improvements — which I don’t feel is necessary getting into — some games actually now have better cloud sync improvement. In other words, if there was a game in your library that you enabled cloud saves with, and picked the game up on another computer, you may have discovered the save file didn’t sync properly. With this new Proton release, this should now be fixed, and you should be able to pick back up from where you left off. Games whose cloud sync behavior has been fixed include:

I told you there was a lot of stuff!

So what do you need to do in order to upgrade to this version of Proton? Well, if your Steam client has been running in the background before the update, all you need to do is restart the client and it should be available. Otherwise, you don’t need to do anything.

In case anyone needs a refresher on how to enable Proton, just go to Steam -> Settings. Under the “Steam Play” section, check the box for “Enable Steam Play for all other titles”. If you don’t see Proton 6.3-6 in the dropdown menu underneath, restart the Steam client and it should be available. Select it, and you’re good to go.

Enabling Proton 6.3-6

Great to see all these improvements Valve, CodeWeavers, and everyone else contributing to this project are continuing to pour into this. By the time we get the Steam Deck, I’m pretty certain Proton will be at the point where it will be a completely transparent experience running just about any game out there. Newcomers to Linux won’t even be able to tell the difference running this than running Windows.

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Nice article. Clearly a lot of work has been put into Proton (and your article!) but I am still very concerned about it. Just this weekend, I went to fire up good old Quake via Steam. I haven’t played probably since Proton first came out. Well, the recent updates completely broke it. I tried a bunch of things, and the only thing that got it going again was by nuking the wineprefix directory, uninstalling the game from Steam, nuking the directory, and finally performing a fresh reinstall. Even when I got it running, multiplayer was busted. I had to install… Read more »


There’s a remastered version of Quake that was released, that’s probably what is breaking things.


Awesome, thanks for the thorough article