Memory usage in Optix 6.0 compared to Optix 5.1

Switching to Optix 6.0 I noticed quite a different memory behavior, compared to the previous release.
The tests have been conducted on Windows 10 pro, on a desktop with a RTX 2080 and on a laptop with a GTX 1070, both with 8 GB of video RAM and using driver 430.
The first change I noticed is that there isn’t anymore a big difference in memory occupation among the three structure acceleration modes “Trbvh”, “Sbvh” and “Bvh”.
The second change is that on the RTX card I can load a much bigger number of triangles before going out of memory, compared to the GTX even if they have the same amount of dedicated memory, suggesting that memory usage has been optimized on RTX cards.
Are those 2 differences to be expected?
Thank you

Hey @t_en. The short answer is yes, those two changes are expected behavior for OptiX 6 with RTX hardware.

With OptiX 6 & RTX, your BVH type is being overridden to use a BVH format that is specific to RT cores. And the new BVH format is more compact than the other older BVH formats.


Thank you for your reply.