Official system requirements

Originally Posted by Novotny

You don't understand the difference between choosing to allow Physx support and running SLI.

Of course I do, you enable physics within the driver, you can select one card to handle this alone. However most modern titles such as Call Of Duty Worl at war allow you to select dual cards within the setup without having to go into the driver, for SLI that is. You may not choose to use this option because you may want to use one card to handle the physics, but the option is within the game non the less.