Spec me a 12 pin power cable for RTX 3090 FE

Quartz · 5 Oct 2021 at 17:30

I want to neaten up my system a little by not having the 12 pin splitter on view. So I want a 12 pin extension cable. OCUK don’t sell them. A quick search turns up quite a few but many say they are not to be used with the 3090 FE.

So spec me.

Infiniteey · 7 Oct 2021 at 21:07

I bought a cable that goes straight from my Corsair SF750 into my 3080 FE from https://www.moddiy.com/products/Cus...ble-for-NVIDIA-RTX-30-Series-Mini-12-Pin.html

Tell them the model of your PSU and choose the Dual 8pin to RTX 12 pin option. You can choose exactly how you want the cable made.

I went for black single sleeved 20cm for my SFF build. Its about a quarter of the amount of cable compared to the original 2x 8pin GPU cable + 12 pin adapter, which actually couldn't fit inside the case so it made it look like my PC was having a hernia.

Quartz · 8 Oct 2021 at 00:30

Duly ordered, thank you.

Hasnain · 12 Oct 2021 at 06:22

Also can recommend the moddiy cable been using it for a almost a year works like a charm.

Quartz · 28 Oct 2021 at 11:39

Grrr... the cable has arrived but it's got the wrong connectors on it. Either it needed female 8 pin connectors on the back end or 9 pin male connectors for my PSU. It has 8 pin male connectors. So I need a converter.

Jay85 · 28 Oct 2021 at 11:43

Was gonna say i have an EVGA 12pin to dual 8pin from moddiy that you could have. I ordered it in anticipation for a FE card way back but it never happened lol.

mickyflinn · 28 Oct 2021 at 11:53

Quartz said:
Grrr... the cable has arrived but it's got the wrong connectors on it. Either it needed female 8 pin connectors on the back end or 9 pin male connectors for my PSU. It has 8 pin male connectors. So I need a converter.

They do a female version , wasnt talking about you my friend

https://www.moddiy.com/products/Cus...on-Cable-for-NVIDIA-RTX-30-Series-12-Pin.html

Quartz · 28 Oct 2021 at 12:10

mickyflinn said:
They do a female version , wasnt talking about you my friend

https://www.moddiy.com/products/Cus...on-Cable-for-NVIDIA-RTX-30-Series-12-Pin.html

That's the male version of the one I ordered.

It's worse than I feared. I took a closer look and - unless I'm an idiot - it is wired incorrectly. He's just wired it up as two 6 pin PCIE cables, so there's no way it can safely provide the power the 3090 requires.

Jay85 said:
Was gonna say i have an EVGA 12pin to dual 8pin from moddiy that you could have.

That's very kind of you. Could you check that yours is not miswired as mine is? I believe forum rules say that discussions of price should be in a private conversation.

Jay85 · 28 Oct 2021 at 12:18

Quartz said:
That's the male version of the one I ordered.

It's worse than I feared. I took a closer look and - unless I'm an idiot - it is wired incorrectly. He's just wired it up as two 6 pin PCIE cables, so there's no way it can safely provide the power the 3090 requires.

That's very kind of you. Could you check that yours is not miswired as mine is? I believe forum rules say that discussions of price should be in a private conversation.

I'll get a pic later tonight and send it to you unless i have one on my phone, if you just cover postage that will do. I'll trust you later about it.

Jay85 · 28 Oct 2021 at 12:22

Found it! Looks to be the same mate, i think that's just how its supposed to be? I've never tested it as i've never had the card to test it on.

Edit: Just realised mines a male to male as well.. probs no good to you.

From what i remember i think this was supposed to plug directly into the psu in my case it was a EVGA 750GQ,

Quartz · 28 Oct 2021 at 12:32

You appear to have the same issue. Wrong gender PCIE connectors and each of those PCIE connectors will carry only 75W rather than 150W. They're missing the Ground connection and the Sense B connection.

Jay85 · 28 Oct 2021 at 12:36

Quartz said:
You appear to have the same issue. Wrong gender PCIE connectors and each of those PCIE connectors will carry only 75W rather than 150W. They're missing the Ground connection and the Sense B connection.

Hmmm wonder why it's like that, i know a few people who are using these without issue.

Jay85 · 28 Oct 2021 at 12:36

I'll see if there connectors are exactly the same as i never looked at theirs.

Quartz · 28 Oct 2021 at 12:39

Hasnain said:
Also can recommend the moddiy cable been using it for a almost a year works like a charm.

Given what I've spotted, could you please take a gander at your cable?

Quartz · 28 Oct 2021 at 13:37

I've raised the issue with them and they're making me a replacement cable. @Jay85 I would check with EVGA before using that cable.

newuser · 31 Oct 2021 at 10:29

Quartz said:
Given what I've spotted, could you please take a gander at your cable?

I've been using one for over six months and it only has six wires in each plug. It's going in to a 12 pin socket. What's the cable layout like on the supplied Nvidia adaptor?

Edited to add - The ones that Seasonic made use the same number of wires as the MODDIY ones.

Quartz · 31 Oct 2021 at 12:04

If the 8 pin plug has only a block of 6 wired with the end two blank then it should only be rated for 75W.

newuser · 31 Oct 2021 at 15:07

Quartz said:
If the 8 pin plug has only a block of 6 wired with the end two blank then it should only be rated for 75W.

Why does losing one ground and one sense pin halve the power rating? ISTR Gamer's Nexus going over the new 12 pin connector and how it related to then current PSUs before the 30 series landed, don't remember any suggestion of an issue.

Quartz · 31 Oct 2021 at 16:06

newuser said:
Why does losing one ground and one sense pin halve the power rating?

The sense pin should tell the PSU how much power to supply and whether or not to supply power on pin 2.

newuser · 31 Oct 2021 at 20:10

Quartz said:
The sense pin should tell the PSU how much power to supply and whether or not to supply power on pin 2.

Thanks for that.

If we're going from a 8 to 8 pin spec where possibly only one connector is in play is it possible that 12 out of 16 wires is ok when 6 are 12 volt and 6 are ground/other? They may have accounted for some redundancy knowing that parts of two 8 pin blocks would be in use.

In real world usage I've had my 3090FE pulling circa 380w with the power limit turned up. Haven't experienced any issues. I've had a feel around the cables and connectors and nothing seems to be getting excessively warm. That's taking into account everything in the vicinity of a 3090 gets somewhat warm.