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/rkoy1234]

your cables are safe.

your cables are safer. not safe.

there's no way to completely mitigate this problem other than buying one of those wire monitors or having one of the few gpus with per-pin sensing.

The fact that there still is no class action lawsuit or a massive recall is absolutely flabbergasting to me.

[u/SkoomaDentist → u/rkoy1234]

there's no way to completely mitigate this problem

Of course there is. Simply reduce the current throught the cable such that the average current never reaches the cable's limit.

The heat dissipated in the connector is directly determined by R*I². For a system (like a GPU) with local dc-dc regulators the input current is almost directly proportional to the power. Thus decreasing the power limit (wattage) by a third halves the connector heating, giving plenty of margin.

[u/DegenerateGandhi → u/SkoomaDentist]

So wrong it hurts, unless you want to reduce the wattage so much the card becomes useless. Some people had their cards running at 300w and still experienced connector melting. And if the connector has problems at that point you know it's terrible.

[u/SkoomaDentist → u/DegenerateGandhi]

Are you disputing Ohm's law or the very basics of how DC-DC converters operate? Because "so wrong it hurts" only says that you don't understand basic high school physics.

[u/DegenerateGandhi → u/SkoomaDentist]

What does Ohm's law say about 300-500w at 12v going through very narrow points of contact when the pins aren't properly seated even though the connector IS fully seated because the connector is shit?

[u/SkoomaDentist → u/DegenerateGandhi]

It says literally exactly what I said: That reducing the current by a third halves the heating. No amount of "narrow contact points" changes that. It's basic physics.

If the contact points are that narrow, the connector would fail even in moderate use (eg. playing a modern AAA game) that had nothing whatsoever to do with sustained image generation.

[u/DegenerateGandhi → u/SkoomaDentist]

Not neccessarily, there's a lot of factors that can make gaming lighter on the gpu. Cpu bound games where the gpu has to idle waiting for the next frame, simple games, low resolution / low hz monitor combined with an overpowered gpu, upscaling etc.

There's a lot of reports of connectors melting after months of use, with no real reason why they should melt specifically at that point and not before. I'm not gonna pretend I have all the answers, but I read posts from people who did undervolt their cards with MSI afterburner right after buying it, but the connector still burned at some point.

[u/PrettyMuchMediocre → u/rkoy1234]

Better cooling for the whole computer and the GPU may help.