Originally Posted by
kalniel
Which isn't the route AMD have gone down really. They've gone fixed function for any kind of performance. There *is* flexibility, but at the cost of just doing it in shaders, which is effectively unaccelerated RT which GPUs have been able to do for years (but don't, because it's too slow).
Nvidia have separate hardware units for both the BVH look up and the intersection, I can't find anything about how flexible they are. If they're fixed function then it's basically the same as AMD, only AMD are using existing texture processors for the first bit and only adding on the second unit. Use of shaders for the scheduling is the same.