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

Nvidia's RTX 5090 power connectors are melting

theverge.com

Post reply on HN
Print view View original

471–480 of 526 posts

Re: Nvidia's RTX 5090 power connectors are melting

#471

Post by stoobs »

malfist wrote: post #339
ryao wrote: post #297

Earlier quoted context omitted.

Amazon lists 1500W models: https://www.amazon.com/electric-kettles/b

And they're probably not real. Take look at any of the clones of the dyson hair dryer and check their proclaimed RPMs, many of them would have the tip of the fan blade spinning at several mach if they actually hit their limit. There's aquarium heaters on amazon that say they're 10kw or more and plug into a 120 outlet. I bought a magnet that is supposed to hold "150 pounds", but pulls off the ceiling (in it's stronges…

The Ninja one and probably the Breville ones will be accurate - I have the same Ninja kettle here in the UK and its 3000Watts vs the US 1500Watts.

Re: Nvidia's RTX 5090 power connectors are melting

#472

Post by mmis1000 »

BigJono wrote: post #13

This shit is so fucking dumb. Sorry for the unhinged rant, but it's ridiculous how bad every single connector involved with building a PC is in 2025. I'm just a software guy, so maybe some hardware engineer can chime in (and I'd love to find out exactly what I'm missing and why it might be harder than it seems), but why on earth can everything not just be easily accessible and click nicely into place? I'm paying mult…

Even a middle school teacher will tell you put large amount of current over a wire is an bad idea though. Remember P=I2R? It should be in the first few class that you learn about electricity.

And nvidia engineers decides to put current originally carried by 24wire (or even 32) into a 12wire connector without change the connector size. Wow it's so surprising that it would burn.

I just don't understand how the f*k the whole thing get approved at first place. It's just insane.

Re: Nvidia's RTX 5090 power connectors are melting

#473

Post by toast0 »

leeter wrote: post #419
sozforex wrote: post #401

Earlier quoted context omitted.

~23A had been measured going going through one of 6 wires/pins in this test: https://youtu.be/Ndmoi1s0ZaY?t=927 Standard requires these connectors to handle 9.5A per pin (9.5 A × 12 V × 6 pin = 684 W). A detailed explanation of this mess: https://www.youtube.com/watch?v=kb5YzMoVQyw

I'm curious, if there are any high level electrical engineers reading this please respond. I wonder if that vertical (as far as the PCB goes) power connector will always ensure that this sort of imbalance will always occur. While we like to pretend that current is even in any given current plane that's not what happens. The impedance of the wires and copper is not perfectly ideal. This is why these connectors have eq…

> This is why these connectors have equal number of grounds, so they have an ideal shortest path and balanced return current path.

These connectors have an equal number of grounds and 12v because the same current flows on both sides, and the required current justifies at least 6 wires at the specified current.

Pci-e 8-pin power is a bit weird, because it's 3 12v and essentially 5 grounds; but that's because it's pci-e 6 pin and a promise that the power supply makers know what they're doing... The extra 2 grounds signal that the PSU designers are aware of the higher current limit, even though the wiring specifications are the same.

Re: Nvidia's RTX 5090 power connectors are melting

#474

Post by ninth_ant »

xnyan wrote: post #326
ninth_ant wrote: post #265

Earlier quoted context omitted.

What was “wrong” is that enough people are willing to pay exorbitant prices for the highest-end gear that Nvidia can do most anything they want as long as their products have the best numbers. Other companies do make products with lower power draw — Apple in particular has some good stuff in this space for people who need it for AI and not gaming. And even in the gaming space, you have many options for good products…

We must be thinking about very different types of games, because even though I’m completely bought into the Apple ecosystem and love my M3 macbook pro and mac mini, I have a windows gaming PC sitting in the corner because very few titles I’d want to play are available on the mac.

Perhaps I phrased it poorly but I was trying to separate out GPU workloads for AI and gaming. The apple ecosystem is very poor for gaming overall, but in their ML and LLM related abilities they have very good performance at a fraction of the power draw of a modern nvidia card.

So the point being, nvidia is optimizing for gamers who are willing to throw top dollar at the best gear, regardless of power draw. But it’s a choice, and other manufacturers can make different tradeoffs.

Re: Nvidia's RTX 5090 power connectors are melting

#476

Post by amluto »

ckozlowski wrote: post #291
kersplody wrote: post #273

12vhpwr has almost no safety margin. Any minor problem with it rapidly becomes major. 600W is scary, with reports of 800W spikes. 12V2x6 is particularly problematic because any imbalance, such as a bad connection of a single pin, will quickly push things over spec. For example, at 600W, 8.3A are carried on each pin in the connector. Molex Micro-Fit 3.0 connectors are typically rated to 8.5A -- That's almost no margin…

Great summary. Buildzoid over on YouTube came to a similar conclusion back during the 4xxx series issues[1], and looks like he's released a similar video today[2]. It's worth a watch as he gets well into the electrical side of things. It's been interesting to think that we're probably been dealing with poor connections on the older Molex connectors for years, but because of the ample margins, it was never an issue. N…

And yet plenty of things around the house use far more than 800W and work fine. The secret is to use a more reasonable voltage.

30V or 36V or even 48V would leave a decent margin for touch safety and have dramatically lower current and even more dramatically lower resistive loss.

Re: Nvidia's RTX 5090 power connectors are melting

#477

Post by amluto »

MBCook wrote: post #398
shawnz wrote: post #364

Earlier quoted context omitted.

What's the proposal here, just convince everyone to stop demanding more powerful hardware?

Stop and try again? Either you’re not going to get a choice, or you’ll need a 240v three phase outlet installed and possibly an expanded electrical panel. Nvidia has been all about “as fast as possible, no compromise” for a very long time now. So was Intel, until the Pentium 4 forced a big reset. At a certain point this stuff is just totally untenable. Throw more amps at it stops being workable. Apple seems to be abl…

Math, please. An 800W load is fine on a 120V 15A circuit with plenty of room to spare. The problem is the 12V connection from the PSU to the card.

Re: Nvidia's RTX 5090 power connectors are melting

#478

Post by lazide »

bongodongobob wrote: post #466
lazide wrote: post #417

Earlier quoted context omitted.

They’re far faster than a stovetop most of the time, have auto shutoff so you can wander away for a minute or two or not pay attention to it and not boil off a lot of water, etc. Many parts of the world, it’s a good idea to boil water before using it for drinking, brushing teeth, etc. So it’s actually really convenient for many use cases besides tea or coffee.

That's fine, but there are no use cases in the US. If we are boiling water, it's for food, and we're doing it on the stove, just like the way everyone else cooks. In the US, there is no use case for a specialized water boiling appliance.

I use it to make oatmeal in the morning. Fastest and easiest option.

Re: Nvidia's RTX 5090 power connectors are melting

#479

Post by deelowe »

Schiendelman wrote: post #455
deelowe wrote: post #366

Earlier quoted context omitted.

No one uses transformers anymore. VRRs are basically mini PCs now. They run firmware and report telemetry and are crazy efficient.

I'm not familiar with this! I've tried to investigate but I just get variable refresh rate. Tell me more?

Voltage regulators. Voltage regulation technology is extremely advanced as even very small efficiency gains can save billions for hyperscalers. Unfortunately, I don't know of any specific products to share as power isn't my domain. I'm only familiar with the space because we sometimes have to pull telemetry directly from the VRs when doing system level RCAs. Some of our BMCs can do this directly via I2C.

Re: Nvidia's RTX 5090 power connectors are melting

#480

Post by snuxoll »

ssl-3 wrote: post #437
snuxoll wrote: post #395

Earlier quoted context omitted.

20a outlets are also expensive compared to 15A ones. When redoing the electrical in the house I inherited I put a dedicated circuit in the living room for the TV/game consoles/etc since my daughter's gaming rig would be going in the living room as well; since I hadn't decided to put the recessed panel for the TV wiring in at the time it was the only outlet on the circuit and code dictates that a 20A circuit with a si…

It has long been my understanding that a single regular, bog-standard 15A duplex (ie, dual outlet) receptacle meets the multi-receptacle requirement of a 20-amp branch circuit. If my understanding is correct, then you overkilled it and you could have saved a few dollars, at least one welli-intentioned rant, and still have been compliant with NEC. A literally-single 15A outlet like a Leviton 16251-W would not pass mus…

Well, the rant still applies either way - the 20A outlets are 2x the cost, that's the big reason why the aren't routinely installed. I was thinking when I embarked on the project "oh, I'll just put 20A ones everywhere because why not?" and immediately decided not to when I looked at the prices for the packs of outlets....
Post reply on HN