Your Brain Runs on 20 Watts. AI Wants a Power Plant

The human brain runs on roughly 20 watts. The world’s fastest supercomputer, LineShine in Shenzhen, draws 42.2 million watts. That gap has become the internet’s favorite argument about AI energy use, and most of it is wrong. The comparison itself holds up.

However, the numbers circulating on social media trace back to a single paper. The most striking one has been misattributed for three years. China just topped the global supercomputer ranking for the first time since 2017.LineShine. Shenzhen. 2.198 exaflops.

2 quintillion calculations per second. 20% faster than the US's El Capitan.built entirely on domestic Chinese CPUs. no Nvidia. no US chips.

no export controls… https://t.co/Tuuk6svl6l pic.twitter.com/fwFKWN0Mr4— IT Guy (@T3chFalcon) June 24, 2026 AI Energy Use: What 20 Watts Actually Buys The 20-watt figure rests on decades of metabolic measurement.