Valve’s Proton software uses several different translation layers to make Windows games playable on Linux systems. VKD3D-Proton is one of those components, which has just received a major update with FSR4 support and other helpful upgrades.
VKD3D-Proton is responsible for translating Direct3D graphics commands into Vulkan API calls, allowing modern Windows games to be playable through Proton. It’s based on the regular DXVK project used by the Wine compatibility layer, but Valve’s fork has more complete DirectX 12 support and other enhancements.
The first major change in VKD3D-Proton 3.0 is the completely rewritten DXBC shader backend, improving compatibility and performance across many games. The release notes specifically called out Red Dead Redemption 2, which “runs just fine now in D3D12 mode.” VKD3D-Proton and the original DXVK project also now use the same DXBC frontend, which should simplify future development for both efforts.
The release notes also said, “Some recently released DXBC based games also only work on the new path. The amount of regressions found the last months in DXBC games has been very minor, but it’s possible there are still bugs in this area. However, given that DXVK uses it now as well, it’s been battle tested quite extensively already.”
This update also introduces support for AMD FidelityFX Super Resolution 4, more commonly known as FSR4. Some games use it for resolution upscaling, but VKD3D-Proton was missing some features that it requires until now. The official Proton builds from Valve will only enable it for RDNA4-based GPUs and newer—there is a working implementation for older AMD hardware, but it currently uses a “quite hacky emulation path” with reduced performance.
The list of other new features is relatively short, as the project explained “we’ve more or less caught up on the things we can feasibly implement.” There’s now support for TIER_4 instructions, tight alignment in the AgilitySDK, and shared resource paths with upstream Wine. Experimental support for D3D12 work graphs has also arrived, which isn’t used in any games yet, but the emulation apparently ” can massively outperform native driver implementations of the feature in many scenarios we’ve tested […] at the cost of some extra VRAM usage.”
Finally, there are performance improvements and bug fixes impacting games like The Last of Us Part 1, Helldivers II, Ninja Gaiden 4, Spider-Man Remastered, Monster Hunter Wilds, Mafia: Definitive Edition, and Rise of the Tomb Raider.
The new VKD3D-Proton version should be integrated into the Proton compatibility layer soon.
Source: GitHub via Phoronix