Mesa 21.3 Lands Initial Radeon Ray-Tracing Support In Open-Source RADV Vulkan Driver

Landing overnight into Mesa 21.3 was experimentally enabling the Vulkan ray-tracing extensions within the open-source Radeon "RADV" driver.

The current conditions for this experimental ray-tracing in RADV are using RDNA2 / Radeon RX 6000 series or newer (GFX 10.3+), using the default ACO compiler back-end and not the AMDGPU LLVM shader compiler, and using the "RADV_PERFTEST=rt" environment variable for enabling the extensions.

When those extensions are met with Mesa Git, the KHR_pipeline_library and KHR_ray_tracing_pipeline support is enabled. However, it is important to note that it's a known issue the RADV ray-tracing implementation isn't very well optimized for performance at this point.

Various games work with RADV's ray-tracing including Windows DXR titles via VKD3D-Proton, but not all and the performance is going to be lacking for a while.

In any case the initial code has landed ahead of the Mesa 21.3 branching next month and the stable release in November.