I guess I misspoke about being 1920x1080 which is a "2K" screen split in two. An 8K screen split in two would be ~4000x4000 per eye which is still 16x as many pixels as I said, plus the 33% increase in frame rate which I didn't include which matches your second one. Although with how embarrasingly parallel it is, I don't think it's as far off as it seems. Especially considering that it's the previous generation graphics cards that can handle current day VR fine so we're 1-2 years into the 9 years we have to wait, and with so many pixels anti-aliasing can probably be turned off completely. You could probably build something today that could do it, it just would be very expensive and I don't think 8K panels at cell-phone size exist yet.