Speaking of over-clocking, has anyone got a chip hashing with an external oscillator yet? If so, could you make it go faster than the internal oscillator would have been running at whatever core-voltage you're running?
I think bitfury had some results from externally driving the chips when he was first testing them for correctness? Would be interesting what fmax we could get out of the chips if we ignored power efficiency.
Power consumption goes up exponentially... I don't think you're going to get much beyond 3GH.
Exponentially with voltage, but linearly with frequency(at identical voltages), correct?
Yeah, that's correct. I'm not sure using an external clock alone is going to help that much. I'm definitely interested to see what folks come up with though!
I imagine, having no professional education on this, that the internal oscillator scales in frequency in a predictable manner. Might be linear, might be exponential, or some other function. I know bitfury showed results where at a certain voltage/frequency, the chip was returning enough errors that a lower frequency was resulting in more overall work. Perhaps the cores required more voltage at that point to be stable? Would have been really neat if the internal oscillator took in a separate Vcc pin so you could tweak each chip's oscillator and core voltage for ideal performance.
Bitfury's chips interest me greatly and make me sad I chose computer science instead of computer engineering while in school.. now I'm stuck reading up on CE/EE college websites at night while pretending I understand what I'm reading.
