Quote from: thejewelrytech on July 09, 2014, 04:42:41 AM

There could also be the possibility that there is equipment out there can't actually solve a block now? What proof is there that all equipment is capable of achieving a best share in the billions and all chips and mining equipment is equal?

Is it possible? Yes. Is it likely? No, and the proof is in the math.

Now obviously the chips and mining equipment aren't 'equal'. Some will be faster (meaning it can make more attempts per second), some will be more energy efficient (meaning each attempt takes less energy), and some will have fewer hardware errors (meaning, well, fewer errors), and if you're lucky you've got one that is all three.

But for any single attempt, a BitFury is just as likely to get a good share / find a block as an Avalon, or a Bitmain, or Minion, or RockerBox or insert-chip-here.

The reason for that is that the output of sha256(block header + nonce) is unpredictable. I.e. you can't tell the chip to only generate results that are within a particular region. It just gets 'a' result and either that's below the threshold, or not (thus no shortcut). If a chip somehow failed to return results that are below a threshold, the chip would need to actually have pathways in it that specifically single those out, either by design or by some very peculiar quirk (thus the 'possible, but unlikely').

If a chip can't scan all possible nonces (e.g. BitFury's hard coded nonce bits), then at some point well into the future there may well be a block that such a chip cannot solve. Thankfully, by then, you probably shouldn't be using such a chip anymore anyway - if for no other reason than that you're likely no longer alive