Rise of the Tomb Raider struggles to maintain 60fps at 4K with a single GTX 1080 Ti, but a series of strategic settings choices allows us to run this title at 30-35fps at 8K, where it still looks spectacular - but it's here where we reach another physical limit of current GPU technology: VRAM. We could only achieve solid performance by running the game's console-level texture assets, not the 4K artwork. GTX 1080 Ti's 11GB simply isn't enough, and judged by today's standards, 16GB looks like the sweet spot. Certainly, that's what Watch Dogs 2's VRAM indicator reckoned would be required to get the job done - we had some initial success with that one, but settings exploration just caused multiple crashes, something we had to contend with throughout the entire testing experience.
...On top of that, 16GB of VRAM is a must. But the fact that we got close to 60fps gameplay in some demanding titles is heartening.