So I'm starting to lean towards the GTX 680 but I was told something odd by the guy at the shop today, he says no matter what a made for mac Graphics card must be installed in slot 2, not slot 1 where the old card was. But why? I'd rather use slot 1, is there a problem with using this slot for any reason or what? (4.1 MacPro, Mavericks) The guy didn't know why but maybe someone here does? Why is it bad to useslot 1 if it was used by the default graphics card? So what's up with that?