Did some searching on this subject and didn't find much, but here's what I do know:

it helps dedicate system resources to the render engine rather than Poser itself.

Makes rendering large scenes easier

My questions are these:

Why isn't Poser set up to do this to begin with?  It's like the difference between playing a game with software excelleration and hardware excelleration.

Why doen't it render in multiple threads even when I have 4 selected?

And is there anything else I could benifit from it?