alt Hacker NewsWell the point is that verification can run in parallel, so if you can verify at 500 Mhz and have twenty of these units, you can run the core at 10 GHz. Minus of course the fixed single instruction verification time penalty, which gets more and more negligible the more parallel you go. Of course there is lots of overhead in that too, like GPUs painfully show.
Right.
So we have 20 verifiers running at 500MHz, and this stack of verifiers is trustworthy. It does reliably-good work.
We also have a single 10GHz CPU core, and this CPU core is not trustworthy. It does spotty work (hence the verifiers).
And both of these things (the stack of verifiers, the single CPU core) peak out at exactly the same computational speeds. (Because otherwise, the CPU's output can't be verified.)
Sounds great! Except I can get even better performance from this system by just skipping the 10GHz CPU core, and doing all the work on the verifiers instead.
("Even better"? Yep. Unlike that glitch-ass CPU core, the verifiers' output is trustworthy. And the verifiers accomplish this reliable work without that extra step of occasionally wasting clock cycles to get things wrong.
If we know what the right answer is, then we already know the right answer. We don't need to have Mr. Spaz compute it in parallel -- or at all.)