Vram isn't that bigger thing really have played games like Killing Floor 2, Metal Gear Phantom Pain, Fallout 4, Skyrim and such. I have never seen my Vram go above 2.5GB on any of these games. I monitored my Vram with MSI Afterburner, most games stayed at 1.2GB most of the time depending on what was happening.
Games like Dota 2, Tf2 and so on were only ever at about 800Mbs+