Well ATI explains your performance issues. Some programs have issues with ATI cards, and Carrara is one of them. I'd recommend if you have the time changing your video drivers. Since I've had similar issues with Carrara and other programs when it comes to ATI and that usually fixes that. Performance is the reason I passed up Softimage, and it was likely due to my ATI cards, of which Softy didn't really have a fix for.