The cost of Chinese miners powered hydro elecricity is around $150 per bitcoin. Some of them will not be profitable when the difficulty rises further.
still profitable with the s7, you see above, i displayed a net profit of about 300 per month, removing 150, will give you a net of another 150
so unless we fall under 150+ it will be profitable for them to continue to mine
S7 is the most efficient miners. Avolon A6 is just below it. Haobtc mining has ordered a lot. It will increase the hashing to 20P early next year.