We did that some time before, and allway´s when Windows memory went over 1.6 billion, we run into problems.
if thats your problem there are maybe two workarounds. First, Windows is optimised for smal aplications like Word. So in a Windows ini, there you´ll find an entry for the highest memory available for real aplications, and this is something about 1.6 billion byte.
so change that entry to a higher entry. We pushed it to three gig, and after this where able to render an animation with more than 6 million polygons with gi and softshadows.
Whell right now with our hands on the new internal version of Vray, 1.45, there is a real solution for real real big scenes. the new raycaster is able to handle realy big amounts of polygons. A friend of mine, “Geddert” who also works at www.lichtecht.com, has posted some images here with one scene using the new instance method of Vray his scene has about 3000000000 (yes three billion) poygons, and still was able to render on a single pc.
so if a big scene is your problem, the near future , thanks to vlado and co. , will solve your problem.