Not a super accurate measurement, but it looks to be about 20A. This is when the chip is around 40C as it gets hotter the current goes up (I was seeing around 22-24A at 60C). I do have the board instrumented so that I should be able to get more accurate results, I just haven't written code to look at that yet

Oh, this was with a core voltage of 0.84V. So looks to be pretty spot-on at 0.67W/GH at 25GH/s (assuming you have decent cooling).