Mesa's RADV Radeon Vulkan Ray-Tracing Performance Continues Improving
Nieuwenhuizen's presentation covered the basics of ray-tracing, how the ray-tracing acceleration is carried out for AMD Radeon RDNA2 GPUs, and the various headaches they have run into for implementing it as well as a software-based implementation for older generations of AMD GPUs.
While RADV recently exposed the Vulkan ray-tracing ray queries extension by default, for the time being the ray-tracing pipelines support is still hidden behind the RADV_PERFTEST=rt environment variable. Bas confirmed the games currently working with ray-tracing on RADV should be Quake II RTX, Control, Deathloop, Resident Evil Village, and Metro Exodus: Extended Edition.
One of the interesting takeaways was the current performance for RADV against AMDVLK's newly-added RT support and the AMDGPU-PRO proprietary driver performance. RADV is still slow with ray-tracing but pending experimental work is helping to close the gap.
To be worked on ahead is supporting separate shader compilation and in turn enabling ray-tracing by default, indirect BHV builds for allowing DXR 1.1 support, and various performance optimizations.
More details on the RADV ray-tracing state via Bas' slide deck and his XDC 2022 presentation embedded below.