GPU vram usage - how does it work?

[Mayh3M]

This was said in the Titan X thread in response to the card hitting high vram in COD AW:

GPUs will cache almost all of the data read by the card and only remove from cache when needed, this is why you can hit 10GB vram usage in a game and yet someone with a 4GB card could run the game without issues caused by a lack of vram. Most on this forum don't grasp this and think if they see a game exceed a certain amount of vram then cards with less vram will experience performance issues.

I have little knowledge of how vram usage works but this explanation seems quite intuitive especially given how 2/3GB cards have no trouble playing games with supposedly higher vram usage in 4GB cards. It would explain why higher resolutions demand more vram, because at any given time, there is more data to cache. On the other hand at standard resolutions we might be overestimating how much vram is really needed.