>Or make them taller, but then you can't cool them easily. Haven't you answered your own question? Your other points are about impossibility - the one I just

>Or make them taller, but then you can't cool them easily. Haven't you answered your own question? Your other points are about impossibility - the one I just quoted, about making chips taller, is about difficulty. If I were the head of Intel I would say "Well. Hmmm. All right. I guess we'd better start making them taller." Moore's law is not a question of "how hard can it be". As you've pointed out, on the current approach it's a question of "It is physically impossible for us to increase transistor count without dropping the clock rate or moving out of roughly a plane. No thanks to Einstein. (My favorite link on this subject: https://www.google.com/search?q=c+%2F+4+ghz https://www.google.com/search?q=c+%2F+4+ghz ) You say "Or make them taller, but then you can't cool them easily." Well then, make them taller and cool them with difficulty. Nobody said it would be easy. Off-hand you could: -> Immerse the taller chip in insane cooling -> Fabricate little duct work between layers and liquid cool at high velocity -> Figure out a way to reduce heat waste usage, e.g.: different substrate, not silicon (pretty insane) -> Possibly combining some of the above points, make it a superconductor. These are insane ideas from me. But then again, I'm not the head of Intel and you've heard a few minutes of thought on me on this topic, where I'm not a chip designer. "When you have eliminated the impossible, whatever remains, however [difficult], is your [roadmap.]"