Question Connect 8 pin pcie cable to 12 pin slot on psu

[CopperCableIsolator]

Dear Internet,

I have recently purchased a radeon rx 6800 and was looking to put it to work. However I missed one detail. I have a sufficient psu with two 12 pin pcie slots, one already in use for my current GPU and connected by a 8 to 12 pin male cable. The 6800 has two eight pin slots however, one I can already plug in but I’m missing a second 12 to 8 pin male cable. I have found one 8 to 8 cable in my scrapbox though and was wondering whether there is a way to make this work. Are there certain pins for certain loads or are they all the same? And if there are which ones do I need to plug in?

Thanks in advance,
CCI

 

[Satan-IR]

No, don't use a cable that (probably) came with another PSU. They're not interchangable and results can be catastrophic.

 

[--SID--]

What's the brand and model of the PSU?

 

[CopperCableIsolator]

What's the brand and model of the PSU?

It’s some flavour of beQuiet and it supplies 600 W I don’t know the exact model though

 

[CopperCableIsolator]

No, don't use a cable that (probably) came with another PSU. They're not interchangable and results can be catastrophic.

Alright, already bought the new cable of of Amazon. But is there really a difference from cable to cable? I mean it’s just copper so if I soldered everything into place, where would be the difference

 

[boju]

Satan did you a favor there and lucky you asked first. Never mix cables unless you know for sure pinouts are the same. Psu industry don't follow wiring standards and if you use a cable from another psu or even off the shelf cables not designed for current psu then big chance of 🔥

 

[Satan-IR]

Alright, already bought the new cable of of Amazon. But is there really a difference from cable to cable? I mean it’s just copper so if I soldered everything into place, where would be the difference

Good idea. Glad you asked before using it.

It's not a matter of cables per se as in they're made of what. On the same note I've seen low quality cables that had aluminium/iron instead of copper ruin PSUs and components. I have also seen other electrical appliances (especially ones with a little higher current draw) damaged or burnt because of low quality cables/wires.

As @boju said the pinouts are not the same (manufacturers are not required by a standard or regulation by some authority to adhere to universally standardized pinout mappings). Granted, if you examine 30 different cables from various vendors you might find a pair that match in terms of pinouts but it's not worth the gamble if you don't have equipment like a multimtere and the knowhow to test them. All this not taking into account the wire gauge. For example, a PCIE 12V cable from a PSU to a graphics card that is going to handle somethign like 12 amps under load needs to be a certain minimum gauge (thickness) or higher.

Mixing cables randomly from other PSUs is, simply, like inserting two/three nails in the wall outlet and shorting them with a screwdriver for example. Best scenario is a fuse pops open. Worst, damaged appliances and wiring in the wall and possibly an electrical fire .

 

[CopperCableIsolator]

Good idea. Glad you asked before using it.

It's not a matter of cables per se as in they're made of what. On the same note I've seen low quality cables that had aluminium/iron instead of copper ruin PSUs and components. I have also seen other electrical appliances (especially ones with a little higher current draw) damaged or burnt because of low quality cables/wires.

As @boju said the pinouts are not the same (manufacturers are not required by a standard or regulation by some authority to adhere to universally standardized pinout mappings). Granted, if you examine 30 different cables from various vendors you might find a pair that match in terms of pinouts but it's not worth the gamble if you don't have equipment like a multimtere and the knowhow to test them. All this not taking into account the wire gauge. For example, a PCIE 12V cable from a PSU to a graphics card that is going to handle somethign like 12 amps under load needs to be a certain minimum gauge (thickness) or higher.

Mixing cables randomly from other PSUs is, simply, like inserting two/three nails in the wall outlet and shorting them with a screwdriver for example. Best scenario is a fuse pops open. Worst, damaged appliances and wiring in the wall and possibly an electrical fire .

Yo, that’s all I needed to hear. Are there specifications within a certain brand. I only ever bought beQuiet PSUs and so I am certain that the cable I own is also from a beQuiet PSU. (Don’t worry I’m asking out of curiosity, not because I wanna do it)

 

[Zerk2012]

Yo, that’s all I needed to hear. Are there specifications within a certain brand. I only ever bought beQuiet PSUs and so I am certain that the cable I own is also from a beQuiet PSU. (Don’t worry I’m asking out of curiosity, not because I wanna do it)

Look at your power supply what is the exact model number.

 

[Satan-IR]

Yo, that’s all I needed to hear. Are there specifications within a certain brand. I only ever bought beQuiet PSUs and so I am certain that the cable I own is also from a beQuiet PSU. (Don’t worry I’m asking out of curiosity, not because I wanna do it)

They can and do change withing same PSU brand. You can't be sure that beQuiet or Corsair or EVGA (whatever brands) use same pinouts for example on all their 8-pin PCIE auxiliary headers on PSU. That's why PSUs (at least good quality standard ones) always come with their own cables.

Again no guarantee. Especially in your case where you're not sure where that spare cable came from. I wouldn't even think about testing/using it.

You should check exact PSU model/part number (printed on the sticker on your current PSU). In the specs page/tab of the shop selling the cables you want to buy check if that exact model/part number is explicitly mentioned.

Buying from more reliable/reputable suppliers or shops like Amazon or NewEgg and from reputable vendors in there would somehow decrease the risk of mistakes or misinformation and misprints on the website.

 

[Joseph_138]

Dear Internet,

I have recently purchased a radeon rx 6800 and was looking to put it to work. However I missed one detail. I have a sufficient psu with two 12 pin pcie slots, one already in use for my current GPU and connected by a 8 to 12 pin male cable. The 6800 has two eight pin slots however, one I can already plug in but I’m missing a second 12 to 8 pin male cable. I have found one 8 to 8 cable in my scrapbox though and was wondering whether there is a way to make this work. Are there certain pins for certain loads or are they all the same? And if there are which ones do I need to plug in?

Thanks in advance,
CCI

Do not save cables from old PSU's. They are not interchangeable, and can damage your PSU, graphics card, or more.