The human brain is dramatically more energy-efficient than AI models like ChatGPT.
Human brain: Uses about 20 watts of power.
ChatGPT (GPT-4): Running a single query can use hundreds of watts when accounting for the entire datacenter infrastructure (some estimates suggest 500–1000 watts per query on average, depending on model size and setup).
If we assume:
20 watts for the human brain thinking continuously,
1000 watts for ChatGPT processing one complex query,
then the human brain is about 50x more energy-efficient (or 5000% more efficient) than ChatGPT per task, assuming equal cognitive complexity (which is debatable, but good for ballpark comparison).
You're absolutely right — watt is a unit of power, not energy. To make a meaningful comparison, we need to estimate how much energy (in joules) each system uses to solve the same task.
Let’s define a representative task: answering a moderately complex question.
1. Human Brain
Power use: ~20 watts (on average while awake)
Time to think: ~10 seconds to answer a question
Energy used:
20
watts
×
10
seconds
=
200
joules
20watts×10seconds=200joules
2. ChatGPT (GPT-4)
Estimate per query: Based on research and datacenter estimates, GPT-4 may use:
Around 2–3 kWh per 1000 queries, which is 7.2–10.8 megajoules
Per query:
7.2
MJ
1000
=
7200
joules
1000
7.2MJ
=7200joules per response (lower bound)
10.8
MJ
1000
=
10
,
800
joules
1000
10.8MJ
=10,800joules per response (upper bound)
Comparison
Human: ~200 joules
ChatGPT: ~7,200 to 10,800 joules
Conclusion:
The human brain is about 36–54 times more energy-efficient than ChatGPT at answering a single question.
There's massive evolutionary pressure for maximizing energy efficiency in brains. I'd like to see LLMs procreate and select for energy efficiency while, ideally, minimizing insanity and maintaining g-factor.
This is fascinating. I mean it's not an argument against LLMs (I have only one brain, even though I'd like to have more). But I really hope that we'll learn much more about how our brains work.
Human brain: Uses about 20 watts of power.
ChatGPT (GPT-4): Running a single query can use hundreds of watts when accounting for the entire datacenter infrastructure (some estimates suggest 500–1000 watts per query on average, depending on model size and setup).
If we assume:
20 watts for the human brain thinking continuously,
1000 watts for ChatGPT processing one complex query,
then the human brain is about 50x more energy-efficient (or 5000% more efficient) than ChatGPT per task, assuming equal cognitive complexity (which is debatable, but good for ballpark comparison).