I currently running it successfully on a Celeron 300Mhz with 256MB. There are some delays such as when going from the Pose Room to the Materials Room. In this case, FireFly seems a bit faster then the standard render engine. I have rendered with raytracing, dynamic cloth and new hair and they all work. Worked with it all day and only had it freeze up once. That was in the D-cloth area but I think I was pushing it with trying to get the cloth to drape over three figures plus a cube. Would I recommend running P5 on a PC this slow as standard practice? Not unless you're very patient. In a week or so, I'll have the money to upgrade to a much faster motherboard and processor. BTW, if folks are having P5 problems and their running Win98 do go to XP. It made a world of difference when I moved over.