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.
Well, cost efficiency does play into the part of considering a purchase, especially if it can preform better than a single card for less cost most of the time. Of course, there are risks associated with multi-GPU setups that anyone that has been building hardware or been into graphics card would know. Unfortunately, some people do not understand that. Some games right now can't squeeze much out of multi-GPU setups but that hopefully will change as more and more developers try and get the issues fixed beforehand on games. Unfortunately, Crysis 2 did not do so.
Also, 24 FPS is smooth for people, and usually, some videos don't go above that limit. I can only agree to that statement if it was the minimum FPS that a player would experience. However, there is a significant proportion of people who like me, would rather play at a higher framerate because there is a significant difference for us going beyond 30 FPS. For me, games will tend to cause a relative decrease in response and movement for me that I don't like and although it is tolerable, I can't game at that framerate for more than half an hour. For these people, I hope you understand that we just need that extra FPS for a better and more comfortable playing experience and that it is subjectively necessary for us, but I can't really speak for everyone.
some good points there.