Well, others have computed the limits. The 3rd reference links to a full article deriving the limits permitted by the laws of physics.
Seth Lloyd calculated the computational abilities of an “ultimate laptop” formed by compressing a kilogram of matter into a black hole of radius 1.485 × 10^-27 meters, concluding that it would only last about 10^-19 seconds before evaporating due to Hawking radiation, but that during this brief time it could compute at a rate of about 5 × 10^50 operations per second, ultimately performing about 10^32 operations on 10^16 bits.
Well, others have computed the limits. The 3rd reference links to a full article deriving the limits permitted by the laws of physics.
You’re not going to get that with silicon technology in the next twenty years, though—that’s the more urgent question.
I agree—I was just answering the question of what the ultimate, inviolable limits are, to establish when the improvements have to stop.