Definition
Mining efficiency is the ratio of energy consumption to hashrate, typically expressed in Joules per Terahash (J/TH) or equivalently Watts per Terahash (W/TH). It is the most important metric for determining long-term mining profitability, as it directly determines electricity costs per unit of hashrate.
The evolution of mining efficiency has been dramatic: early miners operated at millions of J/TH, while modern devices like the Antminer S21 achieve around 15 J/TH. More efficient miners remain profitable longer as difficulty increases and block rewards decrease.
In Simple Terms
Energy efficiency of a miner in Joules per Terahash. Lower is better as it means less electricity per unit of hashrate.
The energy efficiency of a mining device measured in Joules per Terahash. Lower J/TH means the miner produces more hashrate per unit of energy consumed.