I have found that rendering the same scene on poser8 and in poserpro 2010 64bit seperate process has absolutly no difference in render times, i can only assume the 64bit helps with larger scenes due to the access to more ram.

im running pro2010 on:-
i7 860 running on 8 threads
8gb ram
2.3Tb hd
1.8gb nVidia geforce 260

and i have done 10 seperate renderers in both 2010 and p8 and the times remain the same...

Getting old and still making "art" without soiling myself, now that's success.