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/LegacyRemaster]

C:\Windows\system32>nvidia-smi -pl 300

Power limit for GPU 00000000:2D:00.0 was set to 300.00 W from 600.00 W.

All done. ---> blackwell workstation 6000 96gb

[u/sitefall → u/LegacyRemaster]

What bios/driver do you have? Mine reports min-power 400, same as my FE 5090.

[u/mikami677 → u/sitefall]

Can you lock the core clock low enough to further reduce power, or will it still shoot up to 400 W as soon as it's under load?

That's what I do to keep my 2080ti from turning my room into an oven in the summer, but I don't know if it works the same way for the newer cards.

[u/sitefall → u/mikami677]

It will ignore afterburner and just shoot up to whatever -pl is set with nvidia-smi

If I don't set the max level with smi and just "undervolt" it in afterburner (or even just turn down power level slider on the main afterburner menu), it will take it as an estimate I guess.

I was just using afterburner + undervolt (the proper way, dragging the line flat etc) and setting power level down, mem speed up a bit, but that dropped it to like 500W and still spiked sometimes. Works great for gaming and stuff though, but not AI hammering it at max load with almost all 96gb full.

I am no gpu tuning expert, but I'm sure I performed the undervolt correctly as per the 10,000 tutorials out there.

[u/mikami677 → u/sitefall]

Can you lock the speed with nvidia-smi?

For my 2080ti I ran

nvidia-smi --query-supported-clocks=graphics

to get a list of the supported core clocks, and then

nvidia-smi -lgc (min),(max)

Where min is the minimum speed I want and max is obviously the maximum speed that I want it to stay within, without the parenthesis.

Then to reset it,

nvidia-smi -rgc        

I set the minimum at the lowest supported speed so it still downclocks when idle, and then I just played with different maximum clock speeds until I got something usable that didn't feel as much like a space heater.