This is a nitpick, but I don’t think this claim is quite right (emphasis added)
If a silicon-chip AGI server were literally 10,000× the volume, 10,000× the mass, and 10,000× the power consumption of a human brain, with comparable performance, I don’t think anyone would be particularly bothered—in particular, its electricity costs would still be below my local minimum wage!!
First, how much power does the brain use? 20 watts is StackExchange’s answer, but I’ve struggled to find good references here. The appealingly named Appraising the brain’s energy budget gives 20% of the overall calories consumed by the body, but that begs the question of the power consumption of the human body, and whether this is at rest or under exertion, etc. Still, I don’t think the 20 watts figure is more than 2x off, so let’s soldier on.
10,000 times 20 watts is 200 kW. That’s a large but not insane amount of power. You could just about run that load on a domestic power supply in the US (some larger homes might have a 200A @ 120V circuit, for 192 kW of permissible load under the 80% rule). Of course you wouldn’t be able to power the HVAC needed to cool all these chips, but let’s suppose you live in Alaska and can just open the windows.
At the time of writing, the cheapest US electricity prices are around $0.09 per kWh with many states (including Alaska, unfortunately) being twice that at around $0.20/kWh. But let’s suppose you’re in both a cool climate and have a really great deal on electricity. So your 200kWh of chips costs you just $0.09*200=$18/hour.
Federal minimum wage is $7.25/hour, and the highest I’m aware of in any US state is $15/hour. So it seems that you won’t be cheaper than the brain on electricity prices if 10,000 times less efficient. I’ve systematically tried to make favorable assumptions here. Your 200kW proto-AGI probably won’t be in an Alaskan garage, but in a tech company’s data center with according costs for HVAC, redundant power, security, etc. Colo costs vary widely depending on location and economies of scale. A recent quote I had was at around the $0.4 kWh/mark—so about 4x the cost quoted above.
This doesn’t massively change the qualitative takeaway, which is that even if something was 10,000 (or even a million times) less efficient than the brain, we’d absolutely still go ahead and build a demo anyway. But it is worth noting that something at the $60/hour range might not actually be all that transformative unless it’s able to perform highly skilled labor—at least until we make it more efficient (which would happen quite rapidly).
Prior to your comment, the calculation in my head was 12 W × 10,000 × 10¢/kWh < $14.25/hr.
The biggest difference from you is that I had heard 12 watts for brain energy consumption somewhere, and neglected to check it. I don’t recall where I had heard that, but for example, 12 W is in this article. They used the 20% figure, but for resting metabolic rate they cite this which says 1740 kcal/day (→16.9W) in men, 1348 kcal/day (→13.1W) in women, and the article turns 13.1W into 12W by sketchy rounding. That still presupposes that the 20% is valid in both genders. I traced the “20%” back to here which cites papers from 1957 & 1960 (and 1997 but that’s another secondary source). I downloaded the 1957 source (Kety, “The general metabolism of the brain in vivo”. In: Metabolism of the nervous system (Richter D, ed), pp 221–237), and it did cite studies of both men and women, and suggested that it scales with brain mass. I don’t understand everything that goes into the calculation, but they do say 20 W directly, so I certainly feel best about that number, but AFAICT it remains likely that the power would lower for smaller-than-average people including most women. I’m still confused about the discrepency with earlier in this paragraph, but I don’t want to spend more time on it. ¯\_(ツ)_/¯
My intended meaning was that the “power consumption” of “a silicon-chip AGI server” was all-in power consumption including HVAC, but I can see how a reader could reasonably interpret my words as excluding HVAC.
I specifically said “my local minimum wage” because I happen to live in a state (Massachusetts) with high minimum wage of $14.25/hr. (The cost to the employer is of course a bit higher, thanks to legally-mandated employer taxes, sick days, sick-family days, etc.) Granted, we have unusually expensive electricity here in Massachusetts too, but people normally put servers where electricity is cheaper and talk to them over the internet.
Anyway, I clearly messed up especially by not double-checking the 12 watt figure—particularly given that I wasn’t leaving myself much breathing room. Thanks again for your skeptical reading.
I changed the article to say “1000×”. And then that made me feel comfortable changing the punchline to “well below my local minimum wage”. The new calculation is 20 W × 1000 × 10¢/kWh = $2/hr is “well below” $14.25/hr, and then if we allow for higher electricity prices and/or counting HVAC separately it’s still probably fine.
Thanks for the quick reply! I definitely don’t feel confident in the 20W number, I could believe 13W is true for more energy efficient (small) humans, in which case I agree your claim ends up being true some of the time (but as you say, there’s little wiggle room). Changing it to 1000x seems like a good solution though which gives you plenty of margin for error.
This is a nitpick, but I don’t think this claim is quite right (emphasis added)
First, how much power does the brain use? 20 watts is StackExchange’s answer, but I’ve struggled to find good references here. The appealingly named Appraising the brain’s energy budget gives 20% of the overall calories consumed by the body, but that begs the question of the power consumption of the human body, and whether this is at rest or under exertion, etc. Still, I don’t think the 20 watts figure is more than 2x off, so let’s soldier on.
10,000 times 20 watts is 200 kW. That’s a large but not insane amount of power. You could just about run that load on a domestic power supply in the US (some larger homes might have a 200A @ 120V circuit, for 192 kW of permissible load under the 80% rule). Of course you wouldn’t be able to power the HVAC needed to cool all these chips, but let’s suppose you live in Alaska and can just open the windows.
At the time of writing, the cheapest US electricity prices are around $0.09 per kWh with many states (including Alaska, unfortunately) being twice that at around $0.20/kWh. But let’s suppose you’re in both a cool climate and have a really great deal on electricity. So your 200kWh of chips costs you just $0.09*200=$18/hour.
Federal minimum wage is $7.25/hour, and the highest I’m aware of in any US state is $15/hour. So it seems that you won’t be cheaper than the brain on electricity prices if 10,000 times less efficient. I’ve systematically tried to make favorable assumptions here. Your 200kW proto-AGI probably won’t be in an Alaskan garage, but in a tech company’s data center with according costs for HVAC, redundant power, security, etc. Colo costs vary widely depending on location and economies of scale. A recent quote I had was at around the $0.4 kWh/mark—so about 4x the cost quoted above.
This doesn’t massively change the qualitative takeaway, which is that even if something was 10,000 (or even a million times) less efficient than the brain, we’d absolutely still go ahead and build a demo anyway. But it is worth noting that something at the $60/hour range might not actually be all that transformative unless it’s able to perform highly skilled labor—at least until we make it more efficient (which would happen quite rapidly).
Thanks!
Prior to your comment, the calculation in my head was 12 W × 10,000 × 10¢/kWh < $14.25/hr.
The biggest difference from you is that I had heard 12 watts for brain energy consumption somewhere, and neglected to check it. I don’t recall where I had heard that, but for example, 12 W is in this article. They used the 20% figure, but for resting metabolic rate they cite this which says 1740 kcal/day (→16.9W) in men, 1348 kcal/day (→13.1W) in women, and the article turns 13.1W into 12W by sketchy rounding. That still presupposes that the 20% is valid in both genders. I traced the “20%” back to here which cites papers from 1957 & 1960 (and 1997 but that’s another secondary source). I downloaded the 1957 source (Kety, “The general metabolism of the brain in vivo”. In: Metabolism of the nervous system (Richter D, ed), pp 221–237), and it did cite studies of both men and women, and suggested that it scales with brain mass. I don’t understand everything that goes into the calculation, but they do say 20 W directly, so I certainly feel best about that number, but AFAICT it remains likely that the power would lower for smaller-than-average people including most women. I’m still confused about the discrepency with earlier in this paragraph, but I don’t want to spend more time on it. ¯\_(ツ)_/¯
My intended meaning was that the “power consumption” of “a silicon-chip AGI server” was all-in power consumption including HVAC, but I can see how a reader could reasonably interpret my words as excluding HVAC.
I specifically said “my local minimum wage” because I happen to live in a state (Massachusetts) with high minimum wage of $14.25/hr. (The cost to the employer is of course a bit higher, thanks to legally-mandated employer taxes, sick days, sick-family days, etc.) Granted, we have unusually expensive electricity here in Massachusetts too, but people normally put servers where electricity is cheaper and talk to them over the internet.
Anyway, I clearly messed up especially by not double-checking the 12 watt figure—particularly given that I wasn’t leaving myself much breathing room. Thanks again for your skeptical reading.
I changed the article to say “1000×”. And then that made me feel comfortable changing the punchline to “well below my local minimum wage”. The new calculation is 20 W × 1000 × 10¢/kWh = $2/hr is “well below” $14.25/hr, and then if we allow for higher electricity prices and/or counting HVAC separately it’s still probably fine.
Thanks for the quick reply! I definitely don’t feel confident in the 20W number, I could believe 13W is true for more energy efficient (small) humans, in which case I agree your claim ends up being true some of the time (but as you say, there’s little wiggle room). Changing it to 1000x seems like a good solution though which gives you plenty of margin for error.