That much VRAM will not going to give much benefit to the card. Some will said there are new games that use a lot of VRAM but even if they did the gpu core itself was weak to begin with. So before you can turn up the,setting and increase memory usage the card will run out raw power first. In fact even 4gb doesn't really fit much faster card like 960 although the card probably benefit more with 3gb memory instead of 4.