While the Windows version of Forza Horizon 6 performs smoothly across a wide variety of hardware, Linux gamers are encountering significant technical hurdles. Recent reports suggest that the game's underlying architecture is causing major friction for those using translation layers to play on non-Windows platforms.

The Root Cause of Forza Horizon 6 Issues on Linux

Hans-Kristian Arntzen, the developer behind VKD3D-Proton, has recently submitted a series of patches intended to improve compatibility. VKD3D-Proton acts as a vital translation layer, converting Direct3D 12 instructions into Vulkan so that games can function on Linux systems. However, during this process, Arntzen discovered deep-seated flaws in how the game handles its own engine processes.

In a blunt assessment of the game's current state, Arntzen noted: "This game is extremely broken."

His criticisms target low-level coding errors that directly impact stability. Specifically, he identified "use-before-alloc" bugs, where the application attempts to write descriptors to a heap while the GPU is still processing active tasks. In Direct3D 12, proper resource allocation and descriptor writing are mandatory to prevent crashes; failing to follow this sequence can lead to the GPU requesting data that hasn't been fully initialized.

Hardware Impact and Potential Fixes

The technical instability isn't limited to a single hardware manufacturer. The issues appear to affect various setups, including:

  • AMD RDNA 2 (and newer) architectures.
  • Nvidia GeForce RTX GPUs.
  • General Linux environments utilizing the Proton layer.

While Nvidia has acknowledged these issues and promised a fix in an "upcoming driver release," much of the burden currently falls on the community. Interestingly, while many users report struggles on ProtonDB, Steam Deck owners have provided surprisingly positive feedback. This suggests that the game's compatibility with Valve's hardware remains relatively stable despite the engine's flaws.

To mitigate some of the performance hits and stability issues in Forza Horizon 6, players can currently try the following workarounds:

  • Use Proton Experimental via Steam.
  • Disable ray-tracing within the game settings.

As one of the most popular titles on the market, it is highly likely that Arntzen and Valve will continue to refine the translation layer. However, whether Xbox Game Studios will provide necessary engine-level optimizations remains to be seen.