I left it running overnight, and in the morning it was finished at 16000/16000.
I don't know when it was done though, and forgot to check... (should have taken a screenshot too...
)
It looked pretty clean after on hour though, i'm sure 2 hours would have been more than enough, and I used one GTX460 GPU.
We're still working on optimizing the PMC kernel, at this time it's difficult to predict, but I'm hoping we can get 2x speedup after the optimizations are finished,
in a few weeks with the big beta 2.5 release.
Bidirectional pathtracing (and PMC) should make renders like this one converge MUCH faster,
and bidirectional pathtracing + PMC is something we will be starting work on next, after 2.5 is out.
PMC + bidirectional will be ideal, it will be as efficient as the popular standard in CPU based unbiased engines (MLT+bidir),
and this combines with the power of GPUs should really take things to a new level.
Radiance