Free performance gain, if you don't mind beta software.
If you like to live on the edge by installing pre-release software, risks be damned, and own an Nvidia-based graphics card, today's your lucky today. Nvidia just released new 320.00 beta drivers for GeForce graphics cards, and if you install them, the GPU maker says you can enjoy performance gains up to 20 percent. Most of the gains won't be quite as high, though several titles receive a shot in the arm from the new drivers.
The examples Nvidia shared all pertain to GeForce GTX 660 graphics cards and include the following gains for single card setups:
Nvidia also added several new SLI profiles, including ones for Alien Fear, Call of Juarez: Gunslinger, Dead Island: Riptide, Dragon Sword, and a bunch more.