7 ms·
The 500k-ton typo: Why data center copper math doesn't add up
- daeken 9mo agoThis 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.
- eterm 9mo agoIf only there were some kind of international system of standard units.
- blitzar 9mo agoOlympic swimming pools for liquids, times around the the earth for length and number of double decker busses for height.
- RobotToaster 9mo agoFor smaller lengths and radiation bananas are also acceptable.
- lostlogin 9mo agoA good physicist can calculate banana equivalent dose other head. Always ask for it when dealing with radiation.
- brookst 9mo agoDon’t forget cheetahs for velocity and elephants for weight.
- deleted 9mo ago[deleted]
- blitzar 9mo agoA horse as a measure of power and a crocodile bite as a measure of compression strength
- dredmorbius 9mo agoOr vice versa.
- literalAardvark 9mo agoYou 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.
- EA 9mo agoThe original meter (1790s France) was defined as 1/10,000,000 of the distance from the equator to the North Pole along a meridian.
- literalAardvark 9mo agoNot sure if you're correcting me, but yes, that is "a" path around the Earth. It's not the most aesthetic one, but it was at the time the most able to be measured.
- jasomill 9mo agoDon't forget packs of cigarettes as a more convenient unit for measuring volumes significantly smaller than Olympic-sized pools. There is, of course, no more need to standardize on a specific brand or style of cigarette than on a specific depth of Olympic-sized pool.
- coldcode 9mo agoI thought all measurements in data centers were in US football fields.
- Nifty3929 9mo agoFor the floor area or length/width it is, but if you want the height then that's in Empire State Buildings.
- paulddraper 9mo agoThere are standard units, yes.
- testplzignore 9mo agoWe need to standardize on using Earth circumferences as the unit of length. Or better, football fields! (the type of football of course being implied by the website's ccTLD)
- Pinus 9mo agoWe _have_ standardized on Earth circumferences for length, only we divide by 40 million to make the numbers more sane, and got the measurement slightly wrong!
- crote 9mo agoWe should just redefine it to make the speed of light a nice even 300.000 km/s - we are so close already!
- SAI_Peregrinus 9mo agoBut it's already a nice round 10m/s in base 299,792,458.
- jasomill 9mo agoWhy stop there when we could just as easily redefine it to be 1 (new base unit of length)/second or 1 meter/(new base unit of time)?
- Ekaros 9mo agoHow hard would it be to fix this? Could we theoretically add or subtract enough material or make whole thing slightly more dense or less dense to compensate?
- jasomill 9mo agoPer Wikipedia, the discrepancy is approximately 74 km, so digging a ditch with an average depth of approximately 74/2π ≅ 12 km around the circumference of the Earth would theoretically fix the problem. Feasibility and geological implications are left as exercises for the reader. Regardless, I suspect a more cost-effective fix would be to redefine the meter to be a couple "legacy" millimeters longer.
- tlb 9mo agoChecking the arithmetic in every paper published seems like an good use case for LLMs. Has someone built a better version than uploading a PDF to ChatGPT and asking it to check the arithmetic?
- ironbound 9mo agoLLM's are why we're in this mess, they can't do math or count r's
- brookst 9mo agoMore accurate to say they can’t see r’s. They process language but not letters.
- gordonhart 9mo agoModern reasoning models are actually pretty good at arithmetic and almost certainly would have caught this error if asked. Source: we benchmark this sort of stuff at my company and for the past year or so frontier models with a modest reasoning budget typically succeed at arithmetic problems (except for multiplication/division problems with many decimal places, which this isn't).
- RobotToaster 9mo agoInteresting, how have you found they have been performing at more complex things like calculus and analysis?
- speedgoose 9mo agoIt’s on the front page of HN once in a while.
- nine_k 9mo agoAn LLM usually has a powerful digital computer right in its disposal, and could use it as a tool to do precise calculations.
- nine_k 9mo ago> If the "half a million tons" figure were accurate, a single 1 GW data center would consume 1.7% of the world's annual copper supply. If we built 30 GW of capacity—a reasonable projection for the AI build-out—that sector alone would theoretically absorb almost half of all the copper mined on Earth. Quickly doing such "back of an envelope" calculations, and calling out things that seem outlandish, could be a useful function of an AI assistant.
- Gravityloss 9mo agoI think this is exactly the thing that should be done by a person without AI, to check what AI is writing.
- franktankbank 9mo agoNah just spin up an agentic ai proofreading agent on the cloud.
- brookst 9mo agoThat can be true while also seeing value in using an AI to sanity check human-generated claims.
- 9dev 9mo agoUsing 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.
- wongarsu 9mo agoEach 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" capacity on your fingertips
- hireshbrem 9mo agoI wonder how many 'innocent' inaccurate data is taken by journalists to use for their agenda. I think this happens a lot in the age of AI.
- compressedgas 9mo agoThe error in the original article has been corrected. https://developer.nvidia.com/blog/nvidia-800-v-hvdc-architecture-will-power-the-next-generation-of-ai-factories/ https://developer.nvidia.com/blog/nvidia-800-v-hvdc-architec...
- crote 9mo agoWith 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, which at current prices is $0.17 / meter. A 2.4mm2 aluminum conductor has the same resistance, weighs 0.0065kg/m, which at current prices is $0.0195 / meter! Sure, aluminum is a pain to work with, but with a price premium like that there's a massive incentive to find a way to make it work. Copper can't get too expensive simply due to power demands because people will just switch to aluminum. The power grid itself had been using it for decades, after all - some internal datacenter busbars should be doable as well.
- fedeb95 9mo agointeresting, thanks!
- candiddevmike 9mo agoAFAIK Aluminum wires will become a heat liability, especially at higher amps
- lillecarl 9mo agoThicker cables or higher voltage(lower current) is the answer which is why it's used in power distribution networks where they can control the voltage by planning what to transform to.
- greggyb 9mo agoAny wire---of any non superconducting material---will be hotter at higher current flows. You size the wire to the application.
- MSFT_Edging 9mo agoIf 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.
- Fiveplus 9mo agoThe funniest part is beyond the typo, the complete lack of physical intuition from the analysts who circulated this. 500,000 tons is roughly the weight of 1.5 Empire State buildings. If your rack busbars weigh more than the structural steel of the facility housing them, you have a geotechnical engineering crisis on your hands. It is wild that we reached a point where financial modeling is so decoupled from physical reality that nobody paused to ask if the floor would collapse.
- franktankbank 9mo agoI wouldn't be surprised if that part was not really reviewed by an expert. They have the unit mass correct but maybe an editor is like ok but what does this look like for a gw project? It doesn't take more than 3rd grade math and a pocket calculator to do it correctly but journalist hasn't had to fumble that ball before. An expert knows its all too easy for any person to make that mistake and would second guess their own work.
- Aurornis 9mo agoThe world of financial analysis and modeling is broad. It’s common to give these tasks to juniors and expect them to grind through it when the output doesn’t really matter. In this case the output wasn’t actually used for financial modeling. If it had been, it would have been caught immediately when someone put it into a table where they calculated the price or the supply constraints or anything else.
- pseudohadamard 9mo agoAnd anything to do with AI valuation is in la-la-land, so it's not that surprising that a set of made-up values is based on another made-up (or at least erroneous) value.
- matthewaveryusa 9mo agoJust to make it even more real: During covid I added a sub-panel and the wire (more like the sausage given the girth) between the sub-panel and main panel was aluminum because of cost. You just need to be a tad careful at the connection points with copper -- nothing a caring literate person can't handle
- jandrewrogers 9mo agoThese kinds of errors are not rare in the media. Even among engineering fields routine handling of diverse and messy unit systems (e.g. chemical engineering) are relatively uncommon. If you work in one of these domains, there is a practiced discipline to detect unit conversion mistakes. You can do it in your head well enough to notice when something seems off but it requires encyclopedic knowledge that the average person is unlikely to have. A common form of this is a press release that suggests a prototype process can scale up to solve some planetary problem. In many cases you can quickly estimate that planetary scale would require some part of the upstream inputs to be orders of magnitude larger than exists or is feasible. The media doesn't notice this part and runs with the "save the planet" story. This is the industrial chemistry version of the "in mice" press releases in medicine. It is an analogue to the Gell-Mann amnesia effect.
- mrbonner 9mo agoIt’s interestingly related that Amazon is also buying a copper mine: https://www.wsj.com/finance/commodities-futures/amazon-is-buying-americas-first-new-copper-output-in-more-than-a-decade-516a0a1f?st=bVYKsZ&reflink=desktopwebshare_permalink https://www.wsj.com/finance/commodities-futures/amazon-is-bu...
- flakeoil 9mo agoThey don't buy a mine they buy the output.
- NoNotTheDuo 9mo agoAmazingly ironic that in an article about a typo, there is a typo. > "Tat sounds like the ultimate catalyst for the commodities market and copper has been hitting records." "Tat" should be "That", imo.
- zekyl314 9mo agoI saw this too, awesome to report on a typo when you yourself have a typo. What are the odds?
- sidewndr46 9mo agoI interpreted the typo as a meta commentary on the state of journalism in the 21st century.
- NooneAtAll3 9mo agoyou should've made a typo as well, as per tradition
- bradfa 9mo agoWith a higher voltage you can reduce your copper needs by a substantial amount. Seems if copper cost was a concern this would be what these data centers would do.
- sidewndr46 9mo agoAgreed. I was kind of surprised to see 54 VDC mentioned. I am assuming this is low enough to meet some threshold for some kind of safety regulation. In other words, it doesn't shock you just 220 VAC would. I'm not entirely convinced of that however as it turns out bus bars are really dangerous in general. A 54 VDC bus bar won't shock you, but if you drop even a paperclip between the bus bar and a metal part that is grounded it basically disappears instantly in a small blast of plasma. The injury from that can be far worse than any shock you'd receive.
- bradfa 9mo agoMy experience has been that SELV (safety extra low voltage, less than 60V peak and less than 240VA) is considered safe and anything exceeding that needs certain levels of protection. But bus bars generally should be protected regardless of voltage as they carry currents from high current capacity sources so even a lower voltage can be a safety concern. Many server power supplies can take AC or DC input, with the DC input in the 300-500V range as this is comparable to the boost voltage for the AC power factor correction circuit. I just assumed most data centers using DC would be distributing around 400V within each rack.
- JohnMakin 9mo agoEfficient markets!
- deleted 9mo ago[deleted]