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Comment by mikeash | Hacker News Reader

It would make more sense to compare absolute numbers.

A brain uses about 20W. A modern computer has similar consumption, but is many orders of magnitude less powerful.

A single modern CPU can crunch more numbers in a second than every person living on earth combined. Sure there may be things that it's not capable of, but most things it is capable of, it's usually 8-10 orders of magnitude more efficient at.

The brain still tops every CPU at visual processing, which may be its highest throughput interface.

It’s almost like brains and computers are somehow different.

That really depends on how you define "powerful". The computers are less capable in several areas, but also more capable by several orders of magnitude in other areas.

You can’t say it’s less powerful, it’s just different. It’s better at some things, worse at others, mostly because of the software.

Eh, my brain may be much more efficient at problems that involve processing complex sensory input and making split second decisions - but it’s absolute trash at doing complex, repetitive maths.

Our brains are highly specialized, you’re comparing an ASIC strapped to a Z80 with modern general purpose CPU’s.

I'm not sure "powerful" is the word you're looking for. It's order of magnitude less _general_.

Well, evolution has spent millennia optimizing human brains, and millions of years optimizing brains in general, while we have been building computers for ~70 years, about a human lifetime.

And for much of those 70 years, energy efficiency was not the top priority.

Yeah but biology never really had any choice about technology - it was always going to be cells and salts. Its really not about optimization - its about how lucky we are that real intelligence (if that's what we have) can even be achieved using cells and salts.

My brain (or even my whole body) can't play HD video.

No, it plays way better than that.

Our eyes do not see. Our brains do. And the upscalimg from limited data is amazing!

That's largely because the brain is not clocked synchronously, something like 30% of a modern CPU is lost in clock trees. The brain wakes up the bits it needs on demand almost at a per-gate (neuron) level.

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