Great news, iloco! I'm sure you will see a big difference with a dual core CPU and more ram. Happened to me last xmas, and it's amazing. As for 64bit, I bought XP64, and haven't been able to install it on a dual boot, I' pretty gutted I spent 180€ on a program I can't use. Bet the poser shader tree isn't a problem with a 64bit system and 4gigs of ram!