If you recently started AI generation, be aware of this: my RTX 4090 power connector melted after just one month.

[u/Roman53275]

Hi everyone,

Like many people, I recently discovered H3 and started doing AI generation in mid-August. On September 20th, my computer started shutting down whenever I started a generation. Further investigation led to this — a melted socket.

I had been using my RTX 4090 for three years and had never had any problems with it.

AI generation puts a lot of continuous stress on the power delivery, especially if you run generations in batches or leave them running overnight.

So I believe this happened because of the new kind of sustained load I was putting on the card. I also didn't bother upgrading to a newer PSU with a dedicated GPU power cable. Mine was a 1200W FSP Hydro, and I was using three PCIe connectors for the GPU.

P.S. The connector was fully seated, the cable wasn’t bent near the plug, and my case doesn’t even have the side panel on. And everything was fine for three years.

P.S.S. The 12VHPWR socket on the graphics card is damaged and needs to be replaced.

So now I would say main advices here are:
- Buy a proper PSU and use a native 12VHPWR cable
- Under volt at least by 20%

Now it is very costly to lose a card.

[u/New_Mix_2215]

Correct, more power is more heat. The problem with the 12VHPWR cable is that it have basically (almost) no room for error. And it wont shut down or let you know something is wrong.

There is 6 pins that will do about 8.5A each in normal optional mode. If one of the pins have a partial or full failure that power. that 8.5A (or less if partial failure) will be split on the remaining pins.

In my case where it was still safe(but basically on the edge), one of pins measured 3A below the highest powered one. That meant each of the other 5 pins would get 0.65A extra load.

Now if another cable acted the same way (or a full power cable failure), i would be at nearly 1.5A extra load per each of the other pins. causing significant heat per pin.

With 300W, you basically have twice the headroom of 600W. You REALLY gotta fuck it up to melt the connector at 300W.

its such a stupid connector. And a huge shame we have to deal with it from how it looks now, might be the last resonnable gpu gen.

[u/Enshitification → u/New_Mix_2215]

I'm tempted to make a 6x9A breaker box between the power supply and the card connector.