It’s native path tracing from Nvidia samples. Not much added then dropped russian roulette for early path termination and used static depth limit.
Max ray calculation would look like this IMO.
1024[screen-x] * 576[screen-y] * 25[samples/frame] * 8[depth] * 2,28[fps] = 264[Mrays/s]
1024[screen-x] * 576[screen-y] * 25[samples/frame] * 8[depth] * 0,46[fps] = 54[Mrays/s]
It’s far away from 10 giga rays promise ;) I assume that Optix has quite heavy abstraction layer and promised value itself as always was a an marketing point ie. RT Cores can push 10 gigarays if there is no shading and one big triangle in a scene.
I’ve found some interesting discussion over Gigarays and what people were able to achieve:
However this seams a little bit strange. As performance increase in my case grows with scene complexity.
Simple scenes like Cornel Box bring only around 1.2x - 1.4x improvement. Which goes a little bit against some points saying that simple scenes allow to hit values close to advertised number.
Would also love if someone from Nvidia could contribute with some of their benchmark numbers for Optix ie. maximum rays/s output they achieved.
One more thing. Otoy recently released their benchmark preview with RTX, with improvement of 2.7x for PathTracing.