4 min read · Updated 2026-10-25
Mining efficiency and J/TH
Efficiency is the single most important specification of a mining machine. It is expressed in joules per terahash (J/TH).
The definition
A watt is one joule per second, so a machine's power draw in watts equals its hashrate in TH/s multiplied by its efficiency in J/TH. A 200 TH/s machine at 17.5 J/TH therefore draws about 3,500 W.
Why lower is better
With the same hashrate, a machine with a lower J/TH uses less electricity and produces less heat. Over months of operation this gap decides profitability, especially when the network difficulty rises.
Typical values
Older generations ran above 50 J/TH. Current machines are generally in the 15 to 25 J/TH range. Immersion cooling, firmware tuning and clean power can improve the figure on real hardware, including OnlineCryptoMining's.
Frequently asked questions
Does overclocking change J/TH?
Usually it raises hashrate but also raises J/TH, trading efficiency for output.
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