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SOLVED PCI-E pinout Question

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nuubje006

Registered
Joined
Sep 2, 2016
Hi guys,

I'm sleeving my own cables starting from those I got with my Corsair rm750x.
Now the pci-e cables are 8 Pin PCI Express (PCIe) Power Cable Connector to Dual 6+2 Pin PCI Express (PCIe) Power Cable Connector.
The pinouts can be found here.

Now what I want to do is make a 8pin to 6+2pin and a 8pin to 6pin to power my GPU (it has a 6+2 and 6 pin power connector), this would look allot better then the dual.
can I just cut off the extra 6+2 and it will work? (it should right?)

Now my second question is, are the grounds swappable? Also, are the 12V swapable? Right now my cables are connected like this

6+2cable:

7 6 5 | 1
2 3 4 | 1

to 8pin:

5 6 7 X
2 3 4 1

Can I make it the my 8pin is like this:

7 6 5 X
2 3 4 1

It's always the same 12V right? So it should be the same.. But I need to make sure before I blow my GTX1080

Thanks for the help guys!
 
Last edited:

knoober

Member
Joined
Mar 18, 2015
Im curious to get a definitive answer on this from someone who knows for certain, but the reading I have done says that you can change like colored wires - ie any ground can be switched with any other and and 12V can be switched with any 12V, as they all have the same origin point. But that is just stuff I read along the way when I was sleeving my own PSU, not to be confused with real knowledge :)
 
OP
nuubje006

nuubje006

Registered
Joined
Sep 2, 2016
I think it should be possible, but not certain so for now I'm gonna keep the normal pin out :D
 

mackerel

Member
Joined
Mar 7, 2008
For a single PCIe connector I believe it is ok to swap pins of the same type around, but I can't say that with 100% certainty. When I previously looked at high power PSUs, it was said there is some safety regulation on how much current you can produce per rail, and higher power PSUs needed multiple rails to meet that. So the 12V rail for the 24 pin connector might be different from the CPU 12V connector, might be different from the PCIe connectors and you shouldn't necessarily mix across them, but within a single connector it wouldn't make sense to have multiple 12V rails. Some uncommon server PSUs might be the exception there, as a board I was looking at in the past had a special connector with 4x 12V rails on it for example.
 
OP
nuubje006

nuubje006

Registered
Joined
Sep 2, 2016
For a single PCIe connector I believe it is ok to swap pins of the same type around, but I can't say that with 100% certainty. When I previously looked at high power PSUs, it was said there is some safety regulation on how much current you can produce per rail, and higher power PSUs needed multiple rails to meet that. So the 12V rail for the 24 pin connector might be different from the CPU 12V connector, might be different from the PCIe connectors and you shouldn't necessarily mix across them, but within a single connector it wouldn't make sense to have multiple 12V rails. Some uncommon server PSUs might be the exception there, as a board I was looking at in the past had a special connector with 4x 12V rails on it for example.

Thanks for the response!
So you believe that this would be ok? (just did it for the 12V.)
81e42969e5dd30d5fb89d2955cc42012.png

Ow this answer makes me doubt my other answer. If I use 2 PCI-E cables for 1 GPU, this would be different 12V rails yes?
Would this effect my GPU ? or can I just do that?
 

Mr.Scott

Beamed Me Up!
Joined
Jun 9, 2013
Irrelevant. The RM750X is a single rail PSU, so yes, you can swap the 12v lines around. All the 12v lines come from the same rail.