Any way in software to verify 12VHPWR cable power limit?

[The Von Matrices]

I'm having trouble with my RTX 4090's power limit. GPU-Z reports a "PWR" limiter whenever the GPU gets to 450W power draw. The card I have should have a 480W power limit by default, and when I set the power limit to 110%, that should raise it to 530W.

I suspect that the 12VHPWR cable connecting my PSU to my GPU is the culprit because it's seems too coincidental that the power limit is exactly 450W, which would be the cable limit if one of the sense pins was not properly connected. However, I have checked the plug with a multimeter and both sense pins are connected to neutral since there is continuity when touching a sense pin and any other black wire coming from my PSU.

Before I go further with the hardware investigation, is there a way in software to confirm that the cable (and not software) is limiting the card to 450W? I could not find anything in NVIDIA's control panel, in GPU-z, or through an internet search that will report the power limit of the cable.

 

[ir_cow]

Does it have all 4 smart pins (tiny row of pins)? If not it will be limited to 450w.

 

[The Von Matrices]

Does it have all 4 smart pins (tiny row of pins)? If not it will be limited to 450w.

It only has two pins. However, according to https://www.igorslab.de/en/this-is-...on-of-geforce-rtx-4090-works-with-workaround/, only those two pins are needed for 600W.

 

[ir_cow]

Those are sense pins. You need all 4 for 600. Lots of content on this. Maybe if you jump the pins you can bypass this. I wouldn't suggest it though

 

[The Von Matrices]

That doesn't jive with my research. Look at images of manufacturer-supplied 600W 12VHPWR cables. They all have only two sense pins. Examples below:

https://seasonic.com/pub/media/pdf/consumer/datasheet/EN-12VHPWR-Cable.pdf

12VHPWR 600W PCIe 5.0 Dual 8 Pin to 16 Pin Power Cable for Corsair

Buy 12VHPWR 600W PCIe 5.0 Dual 8 Pin to 16 Pin Power Cable for Corsair for $19.99 with Free Shipping Worldwide (In Stock)

www.moddiy.com

 

[oxrufiioxo]

Maybe a damaged cable have you tried the supplied octopus adapter cable?

Is the nvidia supplied cable the one you are already using?

I have a cablemod cable that is 4x8 to 16 pin and has no issues doing 600w.

 

[Dr. Dro]

Igor wrote an excellent article that should clarify how does the 12VHPWR/2x6 system works

Myth Busted: This is how NVIDIA’s 4-way adapter for the 12VHPWR port of the GeForce RTX 4090 really works! | igor´sLAB

Who doesn’t know it, the funny adapter from NVIDIA, with which you can merge four PCIe 6+2 pin cables to be able to run graphics cards with up to 600 watts? If you only connect three plugs…

www.igorslab.de

That doesn't jive with my research. Look at images of manufacturer-supplied 600W 12VHPWR cables. They all have only two sense pins. Examples below:

https://seasonic.com/pub/media/pdf/consumer/datasheet/EN-12VHPWR-Cable.pdf

12VHPWR 600W PCIe 5.0 Dual 8 Pin to 16 Pin Power Cable for Corsair

Buy 12VHPWR 600W PCIe 5.0 Dual 8 Pin to 16 Pin Power Cable for Corsair for $19.99 with Free Shipping Worldwide (In Stock)

www.moddiy.com

I believe your question should also be answered by Igor's article as well. Hint: sense pins 3 and 4 don't really do much.