I'm looking to do some upgrading soon. I currently have an Evga 560Ti 1GB and I want to pair it up with another card. I have always been told to pair your card with another of the same chipset, but as I am researching, I am seeing a lot of systems with 2 completely different chipsets. I recently got Batman: Arkham City and in the setup for PhysX, it recommends NVidia Geforce GTX570 + Dedicated GTX 460 or better for the high setting. I was thinking of getting a 660Ti if possible.