I was just pondering something.

It would seem to me that it'd be possible to buy a Mac Pro with whatever video card you like, and drop a PC video card (ideally from the same manufacturer) into a spare slot. You could run MacOS on the standard video card, and it would (ought to, at least) simply ignore the unrecognized PC video card, then if you boot into Windows you can set the second card (which would be faster; that'd be the reason behind going to all this trouble) as the primary one, and have it render all your games or whatever.

You'd need a KVM switch or a dual-input monitor, but it'd seem to me that it'd work fine... Anyone tried it, or know if it'd work?