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Data centers are transitioning from AC to DC
191–200 of 432 posts
Re: Data centers are transitioning from AC to DC
#192Earlier quoted context omitted.
48vdc was common in phone exchanges. They filled the basement with lead-acid batteries and to could run without the grid for a couple weeks. In turn the phone was 99.999% reliable for decades.
Yeah I always heard that the phone lines carried their own power, and in Florida the phones did keep working when the power went out, but I never knew why. So the grid was always charging up the lead acid batteries, and the phone lines were always draining them? Or was there some kind of power switching going on where when the grid was available the batteries would just get "topped off" occasionally and were only dra…
The batteries and phone lines were one system at -48v with power supplies converting AC power to DC while grid / generator is up.
The batteries are floated at the line voltage nothing was really charging or discharging and there was no switchover.
This is similar to your cars 12v dc power system such the when the car is running the alternator is providing DC power and the batteries float doing nothing except buffering large fluctuations stabilizing voltage.
Re: Data centers are transitioning from AC to DC
#193I've been hearing this line for over a decade, now. "Immersion cooling will make data centers scale!" "Converting to DC at the perimeter increases density!" Yes, of course both of those things are true, and yes, some data centers do engage in those processes for their unique advantages. The issue is that aside from specialty kit designed for that use (like the AWS Outposts with their DC conversion), the rank-and-file…
As seen on HN a few days ago, immersion cooling is dead: turns out the risks of getting sued to oblivion due to widespread PFAS contamination isn't worth it. [0]
DC doesn't have such a killer. There are a decent bunch of benefits, and the main drawback is gear availability. However, the chicken-and-egg problem is being solved by hyperscalers. Like it or not, the rank-and-file of small & medium businesses is dying, and massive deployments like AWS/GCP/Azure/Meta are becoming the norm. Those four already account for 44% of data center capacity! If they switch to DC can you still call it "specialty kit", or would it perhaps be more accurate to call it "industry norm"?
It is becoming increasingly obvious that the rest of the industry is essentially getting Big Tech's leftovers. I wouldn't be surprised if DC became the norm for colocation over the next few decades.
[0]: https://thecoolingreport.com/intel/pfas-two-phase-immersion-...
Re: Data centers are transitioning from AC to DC
#194Earlier quoted context omitted.
the internet really needs to stfu about tesla and get over that oatmeal comic that spawned a billion internet myths. dude was a decent inventor but suffered from chronic mental health issues and, in his lifetime, wasted so much time/energy/money and burned so many bridges with his horrible attitude. there's a reason most people didnt like him in his day, he was a depressed asshole who alienated everyone around him, a…
People need heroes. It's like the Keanu Reeves or Musk era, all the ""badass"" stories about this or that soldier / local hero / w/e that are very often overblown and get further and further away from the initial facts every time they resurface. No hate here, just noticing there is a weird visceral need to distill stories to their most essential, good vs evil, and the Tesla v Edison thing embodies this perfectly I th…
Keanu Reeves and Nikola Tesla to a degree as well, are decent figures.
Aside from all the cult classics Keanu is part of like john wick and the matrix, even discounting that, he is a good person in it of itself who is genuinely humble and might be one of the best persons within hollywood.
What I feel pissed about is that people like Andrew Tate and others like them took the concept of Matrix and the contributions Keanu did within that movie and tried to capitalize on that cult classic decades after in the most toxic form that might be the issue if we are talking about an era
To be honest, Nikola tesla is also a great person within the context of his time. GGP's comment is still true but Tesla's contributions can hardly be reinstated and I'd much rather people believe these to be the heros (Keanu/Tesla) rather than Tate/Musk etc.
If I take anything from Keanu, I would like to take his humility/humbleness.
Re: Data centers are transitioning from AC to DC
#195Earlier quoted context omitted.
I am STILL designing hardware for -48v telco standard. The first thing we do is convert -48 -> 48v. That's 4 square inches of PCB space we waste.
What do you need +48V for?
Well if it's negative 48V the electricty flows out of your circuit and back to the grid, so you need to make it positive to have the electricity come in.
Re: Data centers are transitioning from AC to DC
#196Re: Data centers are transitioning from AC to DC
#197Earlier quoted context omitted.
Can you explain why it's -48 VDC as opposed to 48 VDC with the + and - inputs mislabeled?
Because the chassis is connected to ground (as in, a literal grounding rod hammered into the soil) and by definition your 0V reference point. The crucial difference is the direction in which the current is flowing: is it going "in to", or "out of" a hot wire? This becomes rather important when those wires are leaving the building and are buried underground for miles, where they will inevitably develop minor faults. W…
Do you also happen to why this is not more common? Must be useful for more than just telephone wires.
Re: Data centers are transitioning from AC to DC
#198Earlier quoted context omitted.
Why would we run out of Ga?
There's a component of modern culture that trains and expects people to be extremely pessimistic about long term human development. It results in situations above, where without any further information people just assume by default that were going to run out of a thing and are on some collision course with not just a disaster, but every single conceivable one. (Gallium is a byproduct of aluminum production. We aren't…
My understanding of most elements is if we want more it’s either pretty easy to make from something else we have a lot of, or we need to redo the Big Bang, the latter being, in my opinion, a bit of a disaster scenario.
Re: Data centers are transitioning from AC to DC
#199That is about like aying the band AC DC had its revenge.....
can we stop vibe generating headlines?
Re: Data centers are transitioning from AC to DC
#200Earlier quoted context omitted.
There's a component of modern culture that trains and expects people to be extremely pessimistic about long term human development. It results in situations above, where without any further information people just assume by default that were going to run out of a thing and are on some collision course with not just a disaster, but every single conceivable one. (Gallium is a byproduct of aluminum production. We aren't…
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From your earlier comment, your curiosity was more about what happens after we run out.
In your question you stated the running out as a given fact ("When" we run out, not "if").
If that was what you wanted to say I can't tell you, but that's definitely how it was received and thus you also got the harsh response. Since it reads a lot like doomsday thinking.
(Example: Does that mean when we run out of oxygen there are no more humans?
Why would we run out?)