Question Quick question about connecting cables on a 4090

[emitfudd]

I am installing an MSI 4090 Gaming X Trio. The adapter has 3 8 pin connectors. I have a Seasonic PSU:

Seasonic PRIME 850 Titanium SSR-850TR 850W 80+ Titanium ATX12V & EPS12V Full Modular 135mm FDB Fan Power On Self Tester 12 Year Warranty Power Supply

I have sorted through all the extra cables and have the appropriate ones. The cable end labeled PSU is an 8 pin connector but only has 6 pins in it. The last 2 are empty. The PCI-E end has a 6 pin end and a separate 2 pin end. I assume there is no need to connect the extra 2 pins?

I am using 3 of these in total.

Well now I just read that a 6 pin connector only provides 75W. If I plug in all 8 pins on the PCI-E end of each cable I don't see how it will provide 150W if the PSU end only has 6 usable pins?

Do I seriously need to buy new cables. I would be shocked if my PSU didn't come with all the necessary cables.

 

[SkyNetRising]

Well now I just read that a 6 pin connector only provides 75W. If I plug in all 8 pins on the PCI-E end of each cable I don't see how it will provide 150W if the PSU end only has 6 usable pins?

Extra 2 pins are ground pins. There are already 3 other pins providing ground connection.
Those cables on PSU side can be wired to other occupied pins.

 

[emitfudd]

Extra 2 pins are ground pins. There are already 3 other pins providing ground connection.
Those cables on PSU side can be wired to other occupied pins.

Thanks for the quick reply. So to clarify should I plug in the additional 2 pin connector on the PCI-E end? There is literally nothing in there. If I hold it up to the light I can see right through the holes.

Edit: I should have said there is nothing in the 2 holes on the PSU end of the cable. 8 pin connector but only 6 pins.

 

[SkyNetRising]

So to clarify should I plug in the additional 2 pin connector on the PCI-E end?
There is literally nothing in there. If I hold it up to the light I can see right through the holes.

Solid plug - PSU side,
6+2 plug - graphics card side.

Better show a photo of those plugs.
(upload to imgur.com and post link)

 

[emitfudd]

https://imgur.com/a/2SbzawB

View: https://imgur.com/a/2SbzawB

 

[emitfudd]

Solid plug - PSU side,
6+2 plug - graphics card side.

Better show a photo of those plugs.
(upload to imgur.com and post link)

The PSU side connector left 2 pins empty. I don't know why Seasonic did that?

GPU swap is done and seems to be working properly. The connector going into the GPU is not even slightly warm. I did get one crash to desktop when I fired up Avatar Frontiers of Pandora. Went back in a second time and no crash. I have updated Afterburner and Nvidia driver. I will go back to my original post about swapping GPU's with additional information and questions.

 

[emitfudd]

I never found any solid information on this cable issue so I emailed Seasonic. Reply as follows:

"Thank you for contacting Sea Sonic.

Regarding PCIe cables, by default, whether they are 6-pin or 8-pin, they all consist of 3x +12V pins and 3x Ground pins. When the 2 extra pins are populated, they are most often additional Ground or Sense wires. Your PCIe cables with your 850TR can provide 150W without any problem and even more. You can use them with your NVIDIA adapter to power your RTX 40."