Quote Originally Posted by Darkshade View Post
nVidia's multi GPU technology is called SLI
AMD's multi GPU technology is called CrossFire

Just about every medium end card and above supports the technology, but you also need a mother board that has multiple PCI-E 2.0+ slots and your motherboard specifications if it supports one or the other technology.

In general I recommend getting a single "decent" card over two equally priced "okay" cards because some games don't support GPU scaling that well, like XIV for example only supports it in fullscreen mode.

See http://tinyurl.com/falconguide for more information.
That's fine, I don't really like playing games in windowed mode anyways, kinda takes the feel away from it when you can see the desktop round the edges.