Update
Bitcoin Difficulty Increase Affects Revenue
Bitcoin's projected difficulty increase of 5.68% is expected to reduce the revenue per unit of computing power by 5.37%, all else being equal. For equipment using 20 J/TH and paying 8 cents per kWh, the daily power cushion of $1.37 would become a shortfall of $0.77. The difficulty increase is projected to occur around October 16, and the projected rise would take the hashprice from $39.77 to approximately $37.63 per PH/day.