QUOTE(Human10 @ Sep 9 2015, 06:37 PM)
But with the performance of 960, you probably will be suffer from low unplayable FPS before you able to utilise the 4GB fully, LOL.
You wouldn't want to do that, really.
Whether it's SYSTEM RAM or VIDEO RAM - being fully utilized is not a good thing.
In any case, GTA V i set it to 8x and you see the framerate is bad, drop it to 4x or 2x and IIRC it still takes up more than 2GB VRAM.
Look at Shadow of Mordor, that's totally acceptable framerate on full details but notice how more RAM actually helps the performance.
Bear in mind those are average FPS, it means you have higher max and higher min FPS too.