Why won't smaller, more efficient chips be usable as miners?
I just told you twice. They do not remotely compare to Bitcoin ASICs, and you only want see the magic "SHA-256" word.
We have a professor of Comp Sci who says they will be.
Hilarious.
I'm aware they won't be as powerful, per unit, as mains-powered ASICs. (Although they will be more efficient in hashing per watt.) They're mobile chips. That's not in debate.
Why does that make them unusable?
How on earth is a 14nm general purpose SHA-256 ASIC going to be more efficient that a 14nm ASIC designed specifically to mine bitcoins?
What you are saying makes no sense.
Er, it wouldn't be. I never said a 14nm would be more efficient than another 14nm.
But it will be more efficient than a 25nm. Or a 20nm.
The point is; whatever is the cutting-edge process at the time (14nm, 12nm, 9nm, whatever) - that's
only in the mobiles, stamped out in their hundreds of millions.
You can't afford the latest process (or even obtain it) for small production runs, eg. BTC ASICS. They will always be a couple of generations behind.