Projected Bitcoin difficulty cut offers modest revenue boost but still strains older S19 miners

According to data from Hashrate Index, a projected 6.5% cut in Bitcoin’s mining difficulty slated for mid‑November could raise the hashprice—daily revenue per petahash—from $31.89 to $34.11, a roughly 7% gain. While the boost improves the electricity margin for miners, analysis shows that older Bitmain S19 machines would still need power costs near 5 cents per kilowatt‑hour (kWh) just to break even on electricity alone.

How the difficulty cut translates into higher hashprice

Hashrate Index’s November 9 snapshot recorded difficulty at 148.36 trillion and a spot hashprice of $31.89 per PH/s per day. The platform calculated the effect of a 6.5% difficulty reduction by dividing the current hashprice by the remaining 93.5% difficulty share, arriving at a 7% increase. The estimate assumes Bitcoin’s price, block subsidy and average transaction fees stay constant, and it excludes pool fees, cooling, labor, financing and other operational costs.

Electricity cost ceiling for S19 versus S21

The analysis compares the highest electricity tariff each miner can sustain before electricity expenses exceed gross revenue. Bitmain’s S19‑240 Ca models deliver 90‑95 TH/s while drawing 3,250 W at 25 °C, whereas the newer S21 offers 200 TH/s at 3,500 W. Using the projected hashprice, the S19 rigs would need electricity below roughly 5 ¢/kWh to avoid a negative power‑only margin, while the S21 could become marginally profitable at about 8 ¢/kWh, leaving a thin daily cushion of roughly 10 ¢ after covering power.

What to watch next

The difficulty adjustment will be finalized after the next 2,016‑block retarget, expected around November 13. Market participants should monitor the actual hashprice post‑adjustment, Bitcoin’s price movements, and any changes in transaction fee levels, as these will determine whether the projected revenue gains materialize. Additionally, miners may respond by upgrading to more efficient hardware, which could further reshape the profitability landscape for older equipment.