That's a dual-socket chip. It'll work in the single socket boards too, but it'll be a lot cheaper to just go with:
http://www.newegg.com/Product/Product.aspx?Item=N82E16819117220
Unless of course you're going for a dual-socket monster...
dual socket for the win woooot
i'm looking to do an ultra upgrade on a friends full nividia build version and put it in my hands with extra juice in everyway