Natalie Vock as one of the open-source developers on Valve's Linux graphics team has been spearheading another big ray-tracing performance improvement for the AMD Radeon Vulkan driver. RADV ray-tracing performance improved a lot in 2025 but it's looking like 2026 could be even more exciting.

This past weekend Valve contractor Natalie Vock opened a Mesa merge request to rework the launch ID swizzling of the RADV ray-tracing code to fix Unreal Engine 5's Lumen illumination and reflection system. Besides fixing the ray-tracing code, it can provide a very significant boost for Unreal Engine 5 performance on Linux under Steam Play:

"Should provide a ~4x-8x speedup in UE5's HW Lumen passes, amounting to ~30% total FPS gain in my coarse measurements."

In that merge request a user shared some other exciting benchmark numbers for different games:

Quite some nice gains indeed and for some of the difference whether the game is the difference of being quite playable or choppy.

The merge request is currently under review but will hopefully make it in time for this quarter's Mesa 26.0 stable release that should be out in February.