Hacker News new | ask | show | jobs
by MichaelDickens 108 days ago
OP says one query uses 0.3 Wh. Driving an electric car for 10 miles = 3,000 Wh which is roughly 10,000 Wh per hour.

I'm not sure how many queries is equivalent to an hour of Claude code use, but maybe 5 seconds, which means an hour of continuous use = 216 Wh, or ~50x less than an electric car.

OP has a longer article about LLM energy usage: https://hannahritchie.substack.com/p/ai-footprint-august-202...

2 comments

Beside the point, but 10,000 Wh per hour is kind of an insane unit. It's 10,000 watts. Or 10 kW if you're really into the whole brevity thing.
My point is that Claude might easily be about 50x more energy intensive than normal ChatGPT prompting.
A coding agent runs near-constantly, so of course it'd require a lot more compute than running even, say, a multi-minute query with a thinking model every hour. How much exactly is pretty hard to calculate because it requires some guesswork, but...

For a long input of n tokens from a model with N active parameters, the cost should scale as O(N n^2) (this is due to computing attention - for non-massive n, the O(N n) term is bigger, which is why API costs per token are fixed until a certain point and then start to rise). From the estimates from [1], it's around 40Wh for n=100k, N=100B. I multiply by 2.5 to account for Opus probably being ~2.5x larger than gpt-4o, and also multiply by 2 to pessimistically assume we're always close to Opus's soft context limit of 200k (it's possible to get a bigger context for extra cost, but I suspect people compact aggresively to not have to use it). That gets me 7.2J/t, which at a rough throughput estimate of 20t/s gives me power of 144W. Like a powerful CPU or a mediocre GPU, and still orders of magnitude lower than a car.

[1] https://epoch.ai/gradient-updates/how-much-energy-does-chatg...