I'm a physicist so naturally I do all back-of-the-envelope calculations to one-significant figure with rounding at each step. :) My own estimation is between $

I'm a physicist so naturally I do all back-of-the-envelope calculations to one-significant figure with rounding at each step. :) My own estimation is between $400k per day (hard lower bound) and $800k per day depending on assumptions about hardware efficiency, although around $100k / day was added in the last week in a trend that is continuing, so $1MM/day will very quickly be accurate.