will6871 :
Thank you. They are both EVGA reference but yes one is the SC version and one isn't. Thank you for the fast response. How do you pair them using GPU tweak? Do you have a link to a tutorial?
You can use this for your cards:
http://www.evga.com/precision/
It's the same idea as GPU tweak, if you don't like Precision you can get GPU tweak online or use MSI afterburner.
In the tool you're using to overclock or manage your cards with, there will be something like a "lock" option, which will lock both cards to the same settings.
Once you decide which tool you want to use go ahead and google the tool name and "sli tutorial" so, for example "Precision overclock SLI tutorial" and you'll find a bunch.
If you get stuck let me know.
P.S I'm jealous..