So basically i been thinking about going mac for a looong time, but the graphic cards always put me off...however now with the new imacs and the 680mx graphics chip it may very well be the time for me to make that change...But there is a couple of things im concerned about. 1. How good is the 680mx? will it be able to achieve 7000+ in 3dmark 11,if that is the case im def gonna go get it. 2. The new fusion drives are crazy expensive, is it possible to hook up an external ssd and run the os from that?