As you guys know, some time ago NVidia introduced a technologhy named Scalable Link Interface, shortly SLI. This technology was allowing to use 2 NVidia graphics cads together to improve performance. Now ATI has preparing a new tech named CrossFire as a alternative to SLI. Main difference is connection is making by a external cable in ATI's multiple card solution. For more info, take a look at the http://www.ati.com/technology/crossfire/index.html