Pardon me if this is a stupid question, but I assume that the required efficiency excludes CPU miners, is that correct?
I believe so (effectively), from what I've read so far. But not due to efficiency; instead, due to Stales.That makes sense, thanks for making it obvious.
Someone should start a CPU-only mining pool.
Cheers,
We've got something in the works specifically for CPU miners. We'll keep you posted.