Nvidia's RTX 5090 power connectors are melting

Post by rasz » Tue, Feb 11, 2025, 6:38 PM UTC

Workaccount2 wrote: post #104

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…

I work in power electronics and there are ample connectors that can handle any type of power requirement. What is happening in the computer space is that everyone is clinging to an old style of doing things, likely because it is free and open, and suggestions to move to new connectors get saddled with proprietary licensing fees. D-sub power connectors have been around forever (they even look like the '90s still) and…

Post by lazide » Tue, Feb 11, 2025, 6:41 PM UTC

SV_BubbleTime wrote: post #85

lazide wrote: post #74

Earlier quoted context omitted.

Likely smaller actually.

This isn’t how it works. Your SMPS needs sub-2V output, cool. That means it only needs to accept small portions of the incoming. But, if the incoming is 48V, it needs 48V tolerant parts. All your caps, inductor (optional typically), diodes, the SMPS itself. Maybe there isn’t a sides difference in a 0603 50V capacitor and 10V 0603 capacitor, but there is a cost difference. And it definitely doesn’t get smaller just be…

Post by minzi » Tue, Feb 11, 2025, 6:42 PM UTC

gambiting wrote: post #186

cranium wrote: post #80

There is a real problem with the connector design somewhere: der8auer tested with his own RTX 5090FE and saw two of the cable strands reach concerning temperatures (>150ºC). Video timestamp: https://youtu.be/Ndmoi1s0ZaY?t=883

I've tested my own 5090FE the same way he did(Furmark for at least 5 minutes at max load, but I actually ran it for 30 minutes just to be mega sure) and with an infrared thermometer the connector is at 45C on the GPU side and 32C on the PSU side. I have no idea what's happening in his video but something is massively wrong, and I don't understand why he didn't just test it with another PSU/cable.

Post by eqvinox » Tue, Feb 11, 2025, 6:43 PM UTC

pja wrote: post #49

mlsu wrote: post #33

Earlier quoted context omitted.

Connectors are actually extremely difficult to make. - you have to ensure that the metal connectors take shape and bond to the wire properly. This is done by crimping. Look up how much a good crimping tool costs for a rough approximation of how difficult it can be to get this right. - one plastic bit has to mate with another plastic bit, mechanically. This needs to be easy enough for 99.99% of users to do easily, yet…

> I think next gen we will begin seeing 24V power supplies to deal with this. May as well go the whole hog & jump to 48V. (50V is as high as you can go whilst still being inside the “low voltage” electrical safety regime in most countries IIRC.)

Post by lanstin » Tue, Feb 11, 2025, 6:45 PM UTC

btbuildem wrote: post #184

DannyBee wrote: post #97

Earlier quoted context omitted.

This is because they are trying to parallel like 50amps (it's 12 volt IIRC) over a few conductors to get to 600watts. If it becomes unbalanced due to any number of reasons, none of those individual cables can come close to handling it - they will all generate enough heat to melt lots of things. Conservatively, they'd have to be 8awg each to be able to handle the full load without melting if they ended up taking the f…

Would be trivial to add a fuse / resettable breaker inline.