Memory UsageDoes it make sense for the GeForce GTX Titan X to have 12 GB VRAM? In order to investigate, we ran our full suite of games and recorded the peak memory usage for each game. We tested all resolutions, including 4K. Depending on the game, the highest memory usage happens at 1440p with 4xAA or 4K, and the reported number is the maximum of all four resolutions. The average bar (2799 MB) represents the average of such peak usage, not the average of all games at all resolutions.
Our results clearly show that 12 GB is overkill for the Titan X. Eight GB of memory would have been more than enough, and, in my opinion, future-proof. Even today, the 6 GB of the two-year-old Titan are too much as 4 GB is enough for all titles to date. Both the Xbox One and PS4 have 8 GB of VRAM of which 5 GB and 4.5 GB are, respectively, available to games, so I seriously doubt developers will exceed that amount any time soon.
Modern games use various memory allocation strategies, and these usually involve loading as much into VRAM as fits even if the texture might never or only rarely be used. Call of Duty: AW seems even worse as it keeps stuffing textures into the memory while you play and not as a level loads, without ever removing anything in the hope that it might need whatever it puts there at some point in the future, which it does not as the FPS on 3 GB cards would otherwise be seriously compromised.