Yeah I run P4 Pro and P5 on my Dual G4 768MB. I cannot use P5 as after nearly EVERY operation I get beachballs for about 10 sec. SO ANNOYING. What does Curious recommend? 512 yeah? Yeesh did they even test it on a Mac? I use Pro in Classic, its no where near ideal, but its better than P5. Funny thing tho, I can run a Windows version of P5 in VPC and I kid you not its performance is comprable (if not better, no beachballs) to P5 running native in Panther. Go figure. Shame because I really enjoy using Poser, if P5 could run ok I could finally trash Classic from my HD, oh and if softrabbit made OSX versions of his software.