If you render in the scene window with Seperate Process switched off.... you can see/watch as Poser renders the 4 quarters of the image... depending on how the contents of the scene are placed you can see thte quarters rendering/finishing at different times depending upon what is in them.

The cores of your pooter operate accordingly... some will slow down and/or stop before the others.

"You don't have to be mad to use Poser... but it helps"