I found my main quad core content creator would only run around 50% CPU on a network render and all 4 cores would be 100% on a local render. I stopped using Rendercows until I could get all 5 up to fast dual cores or quad cores with 4gb ram each. (1 upgrade left to go). I will use the same render farm for PoserPro 2010.

ALSO PLEASE DON'T EXPECT IT TO CUT THE RENDER TIME IN HALF. WITH YOUR SETUP EXPECT ABOUT A 15% SPEEDUP