I have never understood why it is when it comes to VRAM some people are continuously dogged about X amount being enough for an amount of time somewhere in the distance as if they have a crystal ball.
This even when money is not an object.
As if given the choice between a 12GB TX and 6GB TI one would pick up the TI because it has 6GB and not the TX because it has 12GB, makes no sense what so ever....
Look, there are games out there which benefit from having huge amounts of VRAM, the more the card has the more Pre-loading of textures it can do and thus the smoother and more fluid the performance.
Also, i can make my own Game which will need the 4GB i have available at 1080P and at decent performance levels, as a matter of fact in one of my creations i am starting to worry about how much VRAM its starting to demand.
With DX12 you will get 15x the Draw-Call through-put, what that means is DX12 can call 15x more objects at any given time than the current DX11 can.
More objects = more VRAM.
I'll stick with my advice and leave it at that