For the most part yes. What do you have? What is your System Spec's? or are you just wondering if you can run games in sl? I have two GTX 550 Ti's in SLI and I can play games with that. I hope this answers your question?
If you have two video cards then you would just set then up in SLI and play your games , there are some games that don't perform with any additional fps because they are not optimized for SLI and in some cases you can do that by going into the Nvidia control panel and activating the SLI feature for that game. Nvidia is always improving the list of games that will use SLI and the game might not have initially been optimized for SLI and then you would have to go into the control panel and do so.