[quote name='boatboy1']Since the card is already older you might want to look into just upgrading your single. Two GPUs doesn't always mean twice the gaming power. I'm not sure in your case specifically so maybe look up some comparison reviews. Keep in mind that you may also need a better psu. Good luck![/QUOTE]
It almost never means twice the power. Mostly around 30% increase, some games don't even acknowledge SLI and you may even see several games perform worse with two GPU's. I'd recommend getting a new card in the 600 series.