I think something is wrong then because I have no option under 3D settings to enable SLI. In the task list there is a Configure PhysX but it just asks me to select a PhysX processor. Gonna download GPU-Z and try that real quick.
Edit: GPU-Z says SLI is disabled? Do I need to install something or what?
You might have to reinstall the software for those options to be available. Try reinstalling the drivers.