Miner efficiency: the J/TH that decides who survives
Efficiency is input power divided by hashrate — 20 J/TH beats 30 J/TH on the same algorithm. It is the number that decides who stays profitable as difficulty rises and prices fall.
One division, labeled
Efficiency = power ÷ hashrate. A SHA-256 miner drawing 3,000 W at 120 TH/s: 3,000 ÷ 120 = 25 W/TH/s — numerically identical to 25 J/TH (a watt is a joule per second; one terahash per second cancels the seconds). Same math for GPUs: a card at 250 W doing 50 MH/s on its algorithm = 5 W/MH.
Why it decides survival
As difficulty grows or price falls, revenue per terahash drops for everyone equally. The operator whose joules-per-terahash is lowest keeps a positive margin longest. At $0.10/kWh, a 25 J/TH machine spends $0.021/hour per TH/s; a 15 J/TH machine spends $0.0125 — a 40% cost edge that no optimization of anything else can match.
- Efficiency is not constant: firmware modes, clocks, and temperatures move it — measure at your settings.
- A lower ratio does not alone prove profitability — purchase price, uptime, and resale still enter the decision.
- When comparing W/GH vs W/TH convert first: 20 J/TH = 0.02 W/GH.
See it live on pow.family
The profitability tool shows your effective $/day per machine at live network numbers — efficiency differences translate 1:1 into the power line.