http://www.hardocp.com/article/2012/..._card_review/5

Look at the last graph in the end

580 sli is unplayable and 680 sli is nearly perfect with about 70% more avg fps and much much better minimum fps
Your tri sli is only about 30-40% faster than the 580 sli and doesn't even come close to 7970 cf or 680 sli
Tis is for bf3


In skyrim your setup is just a little slower than 680 sli but much worse in terms of minimum fps

In batman your setup is nearly as good as 680 sli

In mass effect 3 680 sli is probably better

I see no game where 580 tri sli beats a 680 stock sli at best it trades blows. You can only get increased performance for the extra $250, it isn't possible for you to loose fps in any case

A 680 oc sli can probably get 3d mark 2011 7000-7500+. I doubt you get 7500+ even if you overclock at 24 7 clocks