AMD's HIPRT Working Its Way To Blender With ~25% Faster Rendering

While not part of the upcoming Blender 3.5 release, AMD engineers are working to land their HIP ray-tracing (HIPRT) support within the Blender open-source 3D modeling software that will offer nice rendering speed-ups for AMD RDNA2/RDNA3 GPUs.

While AMD has their HIP back-end within Blender, it currently doesn't make use of ray-tracing hardware found with Radeon RX 6000 series "RDNA2" GPUs and newer. That's akin to NVIDIA's CUDA back-end in Blender while NVIDIA's OptiX back-end with Blender has long allowed making use of the ray-tracing cores for faster render performance on NVIDIA RTX GPUs.

Last year AMD published the HIP ray-tracing library and their engineers have been working to get the HIPRT support squared away within Blender. Last year the hope was for it to be ready for Blender 3.5 but that ultimately didn't pan out. Blender 3.5 is due out for release next week without this AMD ray-tracing support.

Opened two weeks ago is this draft pull request providing work-in-progress Cycles AMD HIP-RT support for hardware ray-tracing. The key takeaways from that PR:

HIPRT enables AMD hardware ray tracing on RDNA2 and above and fallbacks to shader implementation for graphic cards that support HIP but not hardware ray tracing.
...
HIPRT offers an average improvement of 25% in sample rendering rate.

Nice seeing a 25% advantage to this HIP ray-tracing code compared to the existing AMD HIP back-end within Blender. For reference see my past Blender 3.4 HIP benchmarks and prior Blender NVIDIA/AMD GPU benchmarks. AMD really needs this HIP-RT support to pan out for Blender in order to be more competitive to NVIDIA GPUs with this modeling software when using OptiX.

Blender 3.6 is due out at the end of June while the bug-fixing-only period begins on 17 May, so we'll see if AMD HIP-RT manages to land in time. If not then it wouldn't ship until Blender 4.0 in November.