Mix nVidia with ATI for 3 monitor setup?

Question

I am currently working with 2 Monitors and a nVidia GTX560 Ti on an Asus p8p67 motherboard.

Because one of my old monitors is kind of crap, I was wondering if I could buy a new one and setup the old as 3rd monitor. I read that nVidia cards only support 2 monitors so I figured I would buy an additional cheap ATI card like the HD 6670 for the 2nd and 3rd monitor. I don't want to use them for gaming, just watching videos and surfing. Is that possible?
I read something about physx getting disabled if I combine ATI and nVidia. Is this true if I use them seperately like I plan to?

Is that the best way to achieve such a setup? I don't want to spend too much money which I also could be spending on a better monitor.

Answer 1

Well, you haven't mentioned your OS.

Firstly, if you're running vista or better, you should be able to run different drivers for different cards - which makes what you want possible - this won't work on XP I suspect.

PhyX should work if you set your nvidia card as the primary display driver (as you should) and use the AMD card as the secondary - phyx works beautifully with the builtin intel video adaptor as the secondary adaptor on a ivy bridge box - I use a 660 as a primary adaptor and it handles phyx on borderlands 2 at maximum settings.

What you have in mind should work fine, assuming your PSU has the power to power two cards. You can probably go with nearly any supported video card for this, so going with the cheapest option may work here.