assassinscreed.ek1 :
I read on google that some games does not support sli,why?
Correctlion almost no games support multi gpu and if they do almost all do it terribly and make it not worth it.
Because the devs need to make it work togheter with nvidia and amd which is a lot of work for a function very few users will use. A good year will have about 5 games that use sli and give you more than a 30% performance increase without terrible glitches, stutters and whatnot.
Sli and crossfire have basically ceased development in 2016 so no point in getting a second card anymore.