Yet another Olympics video for your enjoyment while waiting for the next Beta build… And this is just step one of the optimizations. 
Is that the voxel engine, new/old top/bottom?
Yes, we did some multi-threading of some portions of the voxel engine. I think Darcy is working on getting it even faster this week as we need it for some production work and time is of the essence.
Wow, I was quite surprised, it seems an order of magnitude faster!
If you watch the progress bar, it is “only” 4 times faster (depending on CPU count). I have 8 CPUs but it does not use them all yet.
Also, the speed up affects the resolution-dependent portion of the process, so increasing the image resolution in Voxel mode causes a much lesser hit than before.
It is actually pretty usable now, but we have hopes to optimize other portions of the rendering process…