6 pin cable from cablemod to my 8 pin psu

[oi you]

So I have an Asus Strix 750W PSU with the back connection as follows:

I bought an extra PCIE cable from Cablemod (exact one is CableMod RT-Series Classic ModMesh 8-pin PCI-e Cable for ASUS and Seasonic (60cm) - Black, in case I was the one who bought the wrong one). According to their compatibility chart, my PSU was listed as compatible with the RT series (I found my cable by clicking on the link next to my PSU model). However, my cable arrived with 6 pins on the PSU end + 2 dummy sockets (See pic below) which branch out into 8 cables/8pins on the GPU end. My question is, is it supposed to only connect 6 out of 8 pins on my PSU? Should there not have been 8 cables/8 pins on both PSU and GPU end? Is this safe to use?

 

[Ryuikko]

Should be the other way around. The 6+2 pin should go into the gpu and the solid 8 pin should go into the psu 

[oi you]

The GPU is a Strix 3080 with 3x8 though so it should be using a full 8, did I buy the wrong cable then? But then it is a "8 pin pcie cable". Also that 6+2 end was labelled PSU. 

[Ryuikko]

35 minutes ago, oi you said:

The GPU is a Strix 3080 with 3x8 though so it should be using a full 8,

Well yes, 6+2 is 8 

 

35 minutes ago, oi you said:

But then it is a "8 pin pcie cable". Also that 6+2 end was labelled PSU. 

Could you take a pic where the 6+2 says psu? It usually should say pcie on it if anything

Besides either of these things the 6+2 should only be Keyed to go into the gpu and shouldn't be able to fit into the psu

Make sure to quote or @Ryuikkoso we can get notifications as well

[Poinkachu]

1 hour ago, Ryuikko said:

Should be the other way around. The 6+2 pin should go into the gpu and the solid 8 pin should go into the psu 

Based on the blurry pic he gave, I think the 2 right most connectors are pinless. (Can see his finger's skin through the 2 holes)
So I think OP is concerned about plugging an "8 but only have 6 actual pins inside" connector labeled PSU to his PSU.

By "Dummy" he meant connector that doesn't have pin(s) inside. Not that addon 2pins on usual 6+2 PCIe connector.

@oi you, compare it with the cable that came with your PSU. If the one that comes with the PSU have pins inside all of them, most likely you need all 8 pins.
Also even if it comes from a big brand, I think it is safer to atleast recheck the pinouts of the custom cable using a continuity mode with multi meter. Compare it with the original cable.

[Spotty]

With 6+2 pin PCIe connectors the extra +2 connector is just a closed ground connection the graphics card uses as a signal to know that the PSU is capable of providing 150w over the 6pin part of the connector. Normally with Seasonic cables both the +2 wires terminate in the bottom right pin on the PSU side. One of the pins is supposed to be empty since there's only 3 12V wires in a PCIe cable. I haven't seen both pins empty but cablemod might be doing something weird.

What's happening with the +2 wires on the other end of the cable which plugs in to the graphics card? 

 

 

 

[Ryuikko]

9 minutes ago, Poinkachu said:

By "Dummy" he meant connector that doesn't have pin(s) inside. Not that addon 2pins on usual 6+2 PCIe connector.

It's odd that both of them don't have pins, though a clearer pic could be a bit more helpful 

[oi you]

Clearer pic, there are no cables even going into the 2 dummy slots. 

 

It does end with 8 pins on the GPU end because they somehow split 2 of the cables in the middle (see pic). I would like to trust Cablemod for their reputation but considering I am risking a 3080, I rather have some confirmation first.

[oi you]

The GPU end does correctly have 8 pins as needed

[Poinkachu]

7 minutes ago, oi you said:

Clearer pic, there are no cables even going into the 2 dummy slots. 

 

It does end with 8 pins on the GPU end because they somehow split 2 of the cables in the middle (see pic)

Looks like they try to skimp by splicing some wire at the middle instead of going full length.
That MIGHT work fine if the spliced ones are just the Ground. But idk about ASUS pinouts.
@Spotty or @Ryuikko may know better.

[Spotty]

7 minutes ago, oi you said:

It does end with 8 pins on the GPU end because they somehow split 2 of the cables in the middle (see pic)

Looks like they're connecting the +2 ground pins mid-cable instead of terminating them at the PSU side connector. Not really sure what the benefit of doing it that way would be. One possible thought would be that because of the sleeving the cables are too thick to terminate two 16AWG sleeved cables in to the one pin on the PSU side, or maybe it's just an aesthetics thing trying to make the cable look cleaner.

Maybe @CableMod has an explanation.

[oi you]

Quote

Also even if it comes from a big brand, I think it is safer to atleast recheck the pinouts of the custom cable using a continuity mode with multi meter. Compare it with the original cable

Hmmm, so the stock cable also has a dummy pin but it's 1 only compared to 2 here. I guess it's safe to have dummy pins then, would the one from cablemod be safe to use? @Ryuikko

[Spotty]

15 minutes ago, oi you said:

Hmmm, so the stock cable also has a dummy pin but it's 1 only compared to 2 here. I guess it's safe to have dummy pins then, would the one from cablemod be safe to use?

On Seasonic power supplies (The Asus Strix is made by Seasonic) where the missing pin is would be a +12V connection on the power supply as the PSU shares the same connectors on the modular panel for CPU and PCIe cables and the EPS12V (CPU power) cable has 4x +12V and 4x Ground wires.

 

The PSU shares the same connectors on the PSU for CPU/PCIe cables.

 

That pin is empty because that missing pin would be the 4th +12V wire but that's not used for PCIe connectors. That's why that pin is missing on your original cable.

 

With that Seasonic cable are there 2 wires going in to that last pin?

 

To understand what is happening you need to look at the pinout for a PCIe connector (this is the end that plugs in to the graphics card). The extra 2 connectors the 8pin has are ground wires. They don't deliver power they just complete a circuit that lets the graphics card know that an 8pin connector is plugged in.

 

 

On your original Seasonic PCIe cable those 2 ground wires will terminate at the PSU where it goes to common ground and completes the circuit. On the Cablemod cable they are wired in to the other ground wires which completes the circuit. All you need is for there to be a physical wire that connects those two pins together, you could stick a paperclip in there and it would do the same job.

 

If you look at this video from Der8auer he uses a +2 connector that is wired together to complete the circuit. You can notice the LED on the graphics card turns white because it is tricked in to thinking there is an 8pin connector plugged in.

 

 

44 minutes ago, oi you said:

would the one from cablemod be safe to use?

Yes.

[oi you]

Thanks to everyone for your help with this and my earlier post asking about cables. After fixing the CPU cabling (builder used 2 EPS cables to connect the 4 pin and half of the 8 pin instead of 1 cable into the entire 8 pin) so I removed 1 and now my 3080 is safely powered by 3 separate cables instead of 2. Booted safely too so fingers crossed i did not fuck up anything

[CableMod]

@oi you fully safe to use, yep! We may at times move around a cable to clean up the pinouts, but rest assured, everything we ship is fully safe to use and fully plug and play because we test and retest everything prior to shipping to ensure it. You'll notice sometimes on your stock cables, you have two wires that terminate into the same terminal at the PSU end, with the pro cables, they're too thick to terminate two wires into the same terminal, that's why we splice them (the heatshrink where 2 wires transition to 1). It's still 8 wires in total though as such though as you can see at the GPU end. Just wanted to explain that as well for anyone who may have questions about that.