I would think your hash rate of the unit is not the same as the pool due to the hardware errors,
only accepted good shares, stale, orphaned, duplicate would be used to calculate your hash rate
over a period of time.

I have my unit running at 555Mhs @ freq 425 stock volatage and want to see how much I can turn
it down and get the least power draw. Anyone dial back yet on a overclocked unit?