My system info:
OptiX Version:[6.1.2] Branch:[r421_00] Build Number: ABI Version: CUDA Version:[cuda100] 64-bit. Display driver: 430.26. Ubuntu 18.04.1. gcc 7.4.0. Cuda 10.0. 2x RTX 2080 Ti
I have been checking the recommendations in the GTC talk: https://developer.download.nvidia.com/video/gputechconf/gtc/2019/presentation/s9768-new-features-in-optix-6.pdf
It suggests to minimize payload size. I am simulating electromagnetic propagation, so I use relatively large payloads (around 100 bytes) that may get larger in the future. I do not use recursive tracing, just iterative tracing, so I was wondering whether I get some benefit by replacing the ray payload with a dummy small payload and use a buffer for storing and updating the real payloads on closest hits.
I have tested it, tracing around 6.5 million rays per launch on a small scene (a few small meshes) and I do not get any conclusive results regarding performance, just a slight decrease.
So this is the question, is it advisable to replace large ray payloads with buffers in some cases?