The 7950 is a single card made up of two cards packed together essentially.. So you are getting 2 7950s, not 4 of them. Also, each one has 1gig of video memory (but since it is two cores on each card, each one really has 512mb, and they all function in an array like format, so you dont really get 1gig of useable video memory). When you run in SLI that doesnt mean you add the video memory together. Also, new nvidia core comes out next september, the g80. you might want to wait for that, unless you have the money today to spend on the two 7950s.