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.
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.