There is also a time value you can set on the renderer so that after 20 seconds (or 2) it stops that bucket and moves on to the next. Of course that was using the old bucket system and not progressive mode.  I haven't tried the timer since they put the new progressive mode in.  But I did put in a request for a detailed log setting to allow you to see what settings gave what results.  But again this was before the new progressive mode.

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13