We estimate the cash flow of mining one bitcoin for two of the most popular machines: Antminer S9 and S19. S9 demands more electricity to mine the same amount of bitcoin than its big brother S19.
Cash flows have decreased by 50% for the S9s and 36% for the S19 since November 9th. Less efficient models, like the S9s, are more susceptible to changes in bitcoin prices or power prices.