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.
Or in percent: 3,600% to 5,400% more efficient
The brain may ultimately be more power-efficient, but the units you want are watt-hours.
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).