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  • Copying over my comment from elsewhere:

    The person on reddit used a third party cable instead of the one supplied with the device.

    https://www.extremetech.com/gaming/psa-dont-use-third-party-power-cables-on-your-2000-nvidia-rtx-5090-gpu

    https://www.reddit.com/r/nvidia/comments/1ilhfk0/rtx_5090fe_molten_12vhpwr/

    It melted on both sides (PSU and GPU), which indicates it was probably the cable being the issue.

    12VHPWR is a fucking mess, so please don't tempt fate with your expensive purchase.

    • Interesting that it lasted two years with their 4090 with no ill effects. Even though the 5090 is higher power draw, I would suspect the contact resistance of the cable was causing heating even before, just not enough to smell or deform the connectors.

    • It's only one wire in the cable, and it's not the wire, but it looks like the pin, or possibly the crimp point on the female pin.

      So a few possibilities:

      • Bad pins. Female pins (sockets) have internal wipers that grip the male pin and there is also the crimp connection. Bad QA on those leads to hotspots in the pin under high current draw. I'd probably go for this explanation, looking at the photos.
      • Bad electrical layout on the card that means that the bulk of the current goes through this pin. Milliohms on the track traces are enough to cause imbalances. This might be balanced out by having a small-but-still-larger resistance in the (standard) cable, which leads to:
      • It looks like thicker cabling is soldered and heatshrinked to smaller cabling that actually goes into the pins in the connector. There's a reason why industrial cable connections aren't soldered. Possibly a solder connection on another cable has broken and hidden in the hearshrink leaving more current to pass through this one.
      • Following from this it's also quite possible that the thicker cable with less resistance , now has less voltage drop across it, and simply allows more current then designed through a connection already at its limit.
      • It's quite possible that there are different pins/connector sets for different current draws. This cable might be using the wrong connector with the same physical size but lower current rating. The fact that the cable has been soldered to skinnier wires in the actual connector suggests this, but it's quite possible that the connector is the right one.

  • Why not just use a connector that is designed for this much and is already cheap and easily available.

    • One plug for the GPU one for everything else. I give it 5 years until this is reality lmao

    • That's designed to work at 120V. The PSU-GPU connector is 12V. I don't know if it'd actually work well -- like, the contacts would have a tenth the conductive capacity, I guess.

      Honestly, the main standardized 12V DC connector that I can think of that we use is the car cigarette lighter, which I don't think normally moves anything like that much power and is terrible, doesn't lock into place, was never intended as a power source. I would like a 12V locking connector that can move a lot of juice.

      https://www.amazon.com/JacobsParts-Cigarette-Lighter-Adapter-Electronics/dp/B012UV3QI4

      Input Voltage: 12 Volts

      Amperage: 2 Amps

      That particular cable and plug will handle 24 watts. I know that you can get higher power ones -- I had to go out of my way to find one that could do 100W.

      My guess is that the 12V problem will never really be addressed and we'll just go to USB-C PD at up to 50.9V for our DC power connector standard. Which I guess works too as long as the amperage doesn't get too high, but that won't be enough to feed a current high-end Nvidia GPU.

      Maybe have, like, multiple USB-C PD connectors in parallel. Three should do it.

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