Yes i dont believe that the total impact of the 'generic' x16 lanes wil be felt until the next gen cards are here. But three years ago i remember reading widely that two 8800 GT in SLI on a x8x8 take a 3-5 percent performance hit....no we are how much farther along with gpu's and there isnt more of an impact?? I believe there is and there are some tests being done that verify it, but its just not to a very large extent, yet. My feeling, however, is that as the gpus mature you will see this becoming a major issue on this chipset for those running sli....hell even if you put a raid card in one of the slots, it will knock your SINGLE gpu down to x8!!
minimum framerrates is where it is rearing its head, you spend alot of time there in gaming...
http://www.bit-tech.net/hardware/cpu...-performance/6
and i agree, those tests were run at a low res!