The improvement made by Valve contractor Natalie Vock for reworking the launch ID swizzling of the RADV ray-tracing code fixes the Unreal Engine 5 illumination and reflection system. As shown in that prior article, there are big performance improvements expected for at least UE5 game titles when running on this now-merged code for the open-source RADV Vulkan driver:
In the past hour the code is now merged to Mesa Git ahead of the Mesa 26.0 code branching / feature freeze expected as soon as next week.
Mesa 26.0 stable should be out in February with the latest RADV ray-tracing improvements and a whole lot more not only for AMD Radeon open-source graphics but also the Intel drivers, the NVK open-source NVIDIA Vulkan driver, and numerous smaller drivers. Mesa 26.0 should pair very nicely with Linux 6.19+ for the early 2026 Linux distribution releases like Ubuntu 26.04 LTS and Fedora 44.