From my experience though on single gpu, the overall performance slows down that late in game.
Though i dont think its gpu related- more like engine wise. Then again 2 cards are better than 1 in most cases.
^^^ Correct, the slowing is NOT related to graphix but rather the number of threads that I believe are in progress at that stage in game. I do know that multicore CPU's should improve late game turn times depending on type and number of cores/threads.
This is one reason why I am eyeing the 6900K Broadwell-E for my next build. This processor SHOULD be available later this year under the 800 dollar mark. However before I do that I was also considering migrating to a good 4K monitor and Frogboy had mentioned to wait till Display Port 1.4 is showing up, which oddly enough it will also this year. My idea is a 4K monitor at 120hz refresh rate with a solid 16 thread I7 and 32 gigs of ram. On paper this system 'should' reduce turn times on an insane map at least by half from what I have now which is an I5 with only 4 cores/threads.
This post was to ask if GCIII graphix improve with multi card/gpus. According to the blog link I posted, most games do not and actually say performance improves with only one card. With that said the only ones who can tell me are the three I mentioned or other folks who are currently running 4K.