Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The 500k-ton typo: Why data center copper math doesn't add up

investinglive.com

Post reply on HN
Print view View original

51–60 of 152 posts

Re: The 500k-ton typo: Why data center copper math doesn't add up

#51

Post by auxym »

y-curious wrote: post #37
crote wrote: post #27

With regards to the copper market: it keeps surprising me that some people seem to assume copper is a hard requirement for conducting electricity. In reality copper is just convenient . We use it because it's easy to work with, a great conductor, and (until recently) quite affordable. But for most applications there's no reason we couldn't use something else! For example, a 1.5mm2 copper conductor is 0.0134kg/m, whic…

I am not an electricity/wiring guy so maybe you can help me understand. I thought aluminum is dangerous to wire with because it is a fire hazard (I bought a home this year and this was a prominent warning in my reading). Is that because it needs to be done very carefully? I imagine most data centers would not mess with a fire risk on such a scale.

It's because aluminium has a higher coefficient of thermal expansion. It expands and shrinks more as it heats, and as those cycles add up it tends to loosen electrical connections. Loose connections have higher resistance, heat up and can cause fires.

That said, there is no reason we can't design better connectors that can withstand the expansion and shrinkage cycles, like spring loaded or spring cage connectors.

Re: The 500k-ton typo: Why data center copper math doesn't add up

#52

Post by MSFT_Edging »

candiddevmike wrote: post #35
crote wrote: post #27

With regards to the copper market: it keeps surprising me that some people seem to assume copper is a hard requirement for conducting electricity. In reality copper is just convenient . We use it because it's easy to work with, a great conductor, and (until recently) quite affordable. But for most applications there's no reason we couldn't use something else! For example, a 1.5mm2 copper conductor is 0.0134kg/m, whic…

AFAIK Aluminum wires will become a heat liability, especially at higher amps

If the two wires are the same gauge, yes. If you size up the aluminum, at the same resistance/current would mean the same amount of power over the length of the conductor and same heat.

Re: The 500k-ton typo: Why data center copper math doesn't add up

#53

Post by greggyb »

kmbfjr wrote: post #41
crote wrote: post #27

With regards to the copper market: it keeps surprising me that some people seem to assume copper is a hard requirement for conducting electricity. In reality copper is just convenient . We use it because it's easy to work with, a great conductor, and (until recently) quite affordable. But for most applications there's no reason we couldn't use something else! For example, a 1.5mm2 copper conductor is 0.0134kg/m, whic…

Aluminum conductors are dangerous unless the entire system is designed for it. It is not a case of switching to something cheaper. Look at the electrical fires of the 1950’s and 1960’s as an example, and that was at household levels of current. Aluminum is used, but everything accounts for the insane coefficient of linear expansion and other annoying properties.

I would imagine most large-scale data center construction projects will include electrical engineers to design the electrical subsystem. A rack's floor footprint is a few square feet. You can put several million dollars of hardware into that rack. A data center will have at least a few racks. It's a very reasonable investment to bring someone in to do electrical design.

Re: The 500k-ton typo: Why data center copper math doesn't add up

#54

Post by lostlogin »

blueg3 wrote: post #32
9dev wrote: post #14

Earlier quoted context omitted.

Using your brain is so vastly more energy efficient, we might just only need half of that 30 GW capacity if fewer people had these leftpad-style knee-jerk reactions.

A Gemini query uses about a kilojoule. The brain runs at 20 W (though the whole human costs 100 W). So, the human is less energy if you can get it done in under 50 seconds.

If humans aren’t more efficient the energy is still used, as they remain alive. Maybe the AI will notice this?

Re: The 500k-ton typo: Why data center copper math doesn't add up

#55

Post by coldcode »

eterm wrote: post #5
daeken wrote: post #2

This sort of mistake is easy to make when you're mixing up your units; if they kept to one system of measure, it would've been trivial to catch, before or after release.

If only there were some kind of international system of standard units.

I thought all measurements in data centers were in US football fields.

Re: The 500k-ton typo: Why data center copper math doesn't add up

#56

Post by EA »

literalAardvark wrote: post #21
blitzar wrote: post #7

Earlier quoted context omitted.

Olympic swimming pools for liquids, times around the the earth for length and number of double decker busses for height.

You jest, but times around the Earth is the actual origin of the Meter. Kinda. The history is quite interesting and well worth checking out. I can't recommend a book on the subject, but I do heartily recommend "Longitude", which is about the challenges of inventing the first maritime chronometers for the purpose of accurately measuring longitude.

The original meter (1790s France) was defined as 1/10,000,000 of the distance from the equator to the North Pole along a meridian.

Re: The 500k-ton typo: Why data center copper math doesn't add up

#57

Post by lostlogin »

9dev wrote: post #49
blueg3 wrote: post #32

Earlier quoted context omitted.

A Gemini query uses about a kilojoule. The brain runs at 20 W (though the whole human costs 100 W). So, the human is less energy if you can get it done in under 50 seconds.

Where does that number come from? Does it factor in the energy required to build the servers used to train the model? Does it factor in… the training?

Hopefully we aren’t doing too much AI training to work out 200 * 1000. If a computer is involved at all it’s disappointing, if AI is used, more so.

Re: The 500k-ton typo: Why data center copper math doesn't add up

#58

Post by 9dev »

lostlogin wrote: post #57
9dev wrote: post #49

Earlier quoted context omitted.

Where does that number come from? Does it factor in the energy required to build the servers used to train the model? Does it factor in… the training?

Hopefully we aren’t doing too much AI training to work out 200 * 1000. If a computer is involved at all it’s disappointing, if AI is used, more so.

It doesn't matter what the model is actually doing at the end of the day, when training and hosting it involves massive amounts of energy.

Re: The 500k-ton typo: Why data center copper math doesn't add up

#59

Post by wongarsu »

program_whiz wrote: post #25
wongarsu wrote: post #22

Earlier quoted context omitted.

Each person uses about 100W (2000kcal/24h=96W). Running all of humanity takes about 775GW. Sure, using or not using your brain is a negligible energy difference, so if you aren't using it you really should, for energy efficiency's sake. But I don't think the claim that our brains are more energy efficient is obviously true on its own. The issue is more about induced demand from having all this external "thinking" cap…

Is there an AI system with functionality at or equal to a human brain that operates on less than 100W? Its currently the most efficient model we have. You compare all of humanity's energy expenditure, but to make the comparison, you need to consider the cost of replicating all that compute with AI (assuming we had an AGI at human level in all regards, or a set of AIs that when operated together could replace all huma…

Obviously we don't have AGI so we can't compare many tasks. But on tasks where AI does perform at comparable levels (certain subsets of writing, greenfield coding and art) it performs fairly well. They use more power but are also much faster, and that about cancels out. There are plenty of studies that try to put numbers on the exact tradeoff, usually focused more on CO2. Plenty that find AI better by some absurd degree (800 times more efficient at 3d modelling, 130 to 1500 times more efficient at writing, or 300 to 3000 times more efficient at illustrating [1]). The one I'd trust the most is [2] where GPT4 was 5-19 times less CO2 efficient than humans at solving coding challenges

1: https://www.nature.com/articles/s41598-024-54271-x?fromPaywa...

2: https://www.nature.com/articles/s41598-025-24658-5

Re: The 500k-ton typo: Why data center copper math doesn't add up

#60

Post by crote »

candiddevmike wrote: post #35
crote wrote: post #27

With regards to the copper market: it keeps surprising me that some people seem to assume copper is a hard requirement for conducting electricity. In reality copper is just convenient . We use it because it's easy to work with, a great conductor, and (until recently) quite affordable. But for most applications there's no reason we couldn't use something else! For example, a 1.5mm2 copper conductor is 0.0134kg/m, whic…

AFAIK Aluminum wires will become a heat liability, especially at higher amps

That's why my calculation example used a 1.5mm2 copper wire but a 2.4mm2 aluminum one.

Aluminum has a higher resistance, which means the same diameter will get hotter than copper. Make the cable thicker and its resistance drops, which means it gets less hot.

Want more amps at the same temperature? Ohm's law still applies: just use a thicker cable.

Post reply on HN