Indeed but also keep in mind preloading things into the vram if it has the room also makes it smoother and less spikes if any. You are also assuming that just because it uses it doesn't mean it needs it. And nvidia and AMD also scale different with different controller widths and memory amounts as well. For nvidia it may not because the way its handled and AMD it may need it for the FPS. For AMD I have seen that normally with the more vram the better fps you get. Anyway I an not going to start arguing over a subject that people have been for quite a few years now. I know which card to get now 
