RAM is your friend. Poser 5 has worked like a freakin dream since getting my new comp with 2 gigs of ram. I had a brief problem with random crashes but that was due to me being a lazy ass and copying my P4 runtime straight over to P5 on my new comp. For what it's worth Poser 5, Firefly with raytracing on seems to render faster than Vue 4 or Truespace 4.3 for equivilent scenes on my new comp.