Will it be possible in the future versions of TG to make preview use multiple cores?
We are going to work on that after 2.0 release. We don't have all of the thread-safe mechanisms in place to allow this just yet. Theoretically we can do it already, but it's not stable in normal usage conditions.
Matt
Great to heard that :)
TG's preview is very helpful but sometimes too slow compared to quick, dedicated render.