And have half the peformance. No thanks.
Half? lol, sorry to ruin your dreams, but only the money you paid for your graphical performance doubled. Your graphical improvements will hardly pass 25% and only in games that handle it properly

The juice is definitely not worth the squeeze about multiple GPU systems, better buy a very good single card then renew it sooner, it'll be much better for your economy bud

http://www.anandtech.com/show/4254/triplegpu-performance-multigpu-scaling-part1/4
NOW SHUT UP.
fine, good for you, and especially those whom you gave your money for, because it's not a benchmark you're playing, it's a game which DOESN'T NOT handle multi-gpu properly. Too bad isn't it? Your improvement does not depend on a bench result, it depends on how good a specific game handles it.
Now, as you told me to shut up which is of course the ultimate settling argument, I would like to show you something that you could notice in seconds if you would have took the time to read just a bit the page you linked me.
If you take a look at the minimum framerate of a game like Crysis:warhead, in a full HD resolution (or about, 1920 x 1200 actually), you'll notice that one of the lowest results is around 40fps, with only one card, and using 3xSLI helps to rise until 46 fps... 6fps earned by buying 2 more cards....
of course with some other cards, you get some real improvements with 2xCF, but if you goes in 3xCF... then the improvement... decrease!!! No man, are you being serious with me? Read what you link before you tell people to shut up and appear yourself as an idiot.
And just for your personal culture... above 24fps, it's fluid for an human eye... so if 30fps at minimum framerate isn't enough for you, it's not an hardware retailer you need, it's a shrink to fix your ego problem.
I'm telling you this because I tried multi gpu before you did, trust me, and I can assure you that you'll get more satifaction in enjoying playing very nicely a game like crysis 2 with an high end performance standalone graphic card, knowing you will have spent a reasonable amount of money, instead of encoutering issues (like you do right now) with 2 or more expensive cards without being able to get the same result before ages.