Separate video cards for OS X and Windows?

My 18month old mac pro's 7300gt card is well past it, and I need to upgrade simply for playing games in Windows.

I've read this http://forums.macrumors.com/showthread.php?t=231318 which is an interesting post if you haven't seen it, but while it hints at my plan it doesn't quite confirm anything.

I don't use any big processing power in mac osx, I simply run 2d audio editing programs.
I want to move my 7300gt to one of the slower pci-e slots and use it to run osx. Could I then buy a regular pc windows designed video card, put it in the x16 pci-e slot and use it only for windows? Would it work?

From my knowledge, I thought all of the PCI slots were 16x. They all can't perform at 16x which is why they are user configurable. This allows the user to tell the computer how much power each slot gets.

I don't know of any problem if your going to use a Windows card if your booting or using Windows. It should work perfectly. Using it for OS X is where the issue is.

Thanks for the link, very cool!

So you can configure the slots then? Any idea how you'd go about doing that?

I need to think about how i'd go about setting it with the screens too. I'm using 2 monitors at the moment, is there a switching box that would take 4 video inputs (2 from each card)?

Link
I want to take a look at this to better understand what this all means but I am not infront of my Mac. Seems interesting though.

Good link that - I'd check if wasn't in windows! I don't know if my 7300gt is a x16 card or not, I suspect not; but even if it was would it work in a x2 slot fine? Surely it would, but just at a slower rate? Then I could run a more up to-date windows configured video card in the x16 slot.

I might just have to take the plunge and buy a card, see what happens. If I buy it from a shop and explain the deal they might let me bring it back if it doesn't work

You can configure it to have one 16x slot and one 8x slot. The 7300 GT will work fine at any speed, it will just perform a lot slower.
I've seen a YouTube video of a guy using a Windows 8800 GT to play a Windows game. Really, you should have no problems running Windows video card.

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