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How much energy does Llama 3.1-405B use?

Meta AI · released 2024-07-23

Llama 3.1-405B uses about 0.213 Wh, 0.903 Wh of electricity to answer a typical question. That places it 219 of 277 among the models we can measure, and every figure here is calculated the same way as every other model.

A typical question
0.213 Wh, 0.903 Wh
A long, complex answer
4.97 Wh, 21.1 Wh
Capability
128.8
Energy rank
219 of 277

How capable is it, really?

The capability figure of 128.76 is a composite over 58 benchmarks, Epoch AI's Capabilities Index, which folds in software engineering, agentic tool use, long-context comprehension and creative writing as well as science reasoning. It is one number standing for a lot of separate tests, so treat a small gap between two models as noise rather than a ranking.

No human head-to-head votes exist for this model. It has been benchmarked but not, as far as we can tell, put in front of people to compare against anything else, worth knowing before treating its scores as a verdict on its answers.

What this figure is

Day-one estimate  Calculated from an estimated parameter count, the maker hasn't published one. Every model on this site is calculated the same way, so the comparison holds even where the absolute value carries uncertainty. Our figures are good to roughly a factor of two to three, which is why we only ever state a difference of 5× or more.

We cannot pin this one down. Meta AI has never published how Llama 3.1-405B is built, and the two plausible answers are far apart, which is why a range is shown rather than a figure. It is listed because leaving it out would reward the silence, and it is barred from every headline claim on this site.

Is there a better choice?

A lighter model that does the job
Anthropic · capability 159.0. It scores higher than Llama 3.1-405B on Epoch's Capabilities Index (158.98 against 128.76), the composite over 58 benchmarks that the capability figure above comes from, and uses about 20× less energy per answer: 0.515 Wh against 10.2 Wh.

What Meta AI publishes

Energy cannot be worked out without knowing how big a model is. Of the 24 models from Meta AI that we track, 12 can be assessed at all, the rest publish too little for anyone outside the company to calculate anything.

Where these figures come from

Capability and the roster come from Epoch AI, whose Capabilities Index is the 58-benchmark composite quoted above. Energy is calculated with EcoLogits and calibrated against laboratory measurements from ML.ENERGY. Human preference comes from LMArena. All four are public and free; the full method is here.

These figures are published under CC BY 4.0, use them anywhere, including commercially, with credit to The AI Footprint.

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Or work out what a year of using it adds up to, for you or for a whole organisation.

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Figure calculated 2026-10-17 · how these numbers are made · the full comparison of 277 models