I know this will sound incredibly stupid, but I don't really understand the concept of multiple cores. I have a 2.16 core 2 duo macbook, and am thinking of upgrading to something like a dual or quad 2.4 mac pro. Does this mean that I get .34 more speed, or 7.44 more (2.16 versus 4 x 2.4)? Could somebody just clarify how this system works, and how to analyze true processor speeds? Thanks!