Question Hopefully a quick basic PSU question

Discussion in 'Computer Components' started by loz_the_guru, Oct 11, 2018.

  1. loz_the_guru

    loz_the_guru
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    Hi all,

    Hopefully a fairly easy to answer question. I have a longish graphics card, which takes a 6-pin PCIE power cable. My PSU is modular, and i've included an image of the ports below. The simplest option would be to use the red ports with an 8 to 6 pin cable, however as the graphics card is so long these are covered due to the design of my case (a Node 304).

    My question is this - can I use the black ports in the centre of the power supply with a 6-pin to 6-pin, red ended cable to power the graphics card, or will they supply an incorrect voltage? If I can't do this i'll need to replace the PSU, which i'd rather not do unless necessary. If it helps, currently two of the central 6 pin ports are supplying power to my HDDs.

    Finally, in case it helps further, this is my PSU, and this is an image of the ports in question.

    Thanks all!
     
  2. EndlessWaves

    EndlessWaves
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    The connections at the power supply end of the modular PSU aren't standardised. If your PSU manufacturer provides a cable for that model that connects to one of the black ports and has a PCI-E 6-pin connector on the other end then it'll be fine.

    If you're talking about some random cable off ebay that uses matching connectors then it's not a good idea. It'll likely feed the wrong voltage to the graphics card and blow something up.

    I guess you can't even mount it upside down as the motherboard cable comes out the other end.

    While you're unlikely to get something off the shelf, you probably could construct a custom cable. Those PCI-E type connectors are typically rated for 8A and you'd need to feed 3x2A through the single 12V output. That doesn't guarantee the circuitry inside the PSU is rated for that, but [email protected] out of a peripheral cable (which is what I'd expect it to be for with those voltages) should be within the bounds of what a decent PSU is designed for.

    I'd suggest asking in a modding forum if that possibility interests you, they'll be able to give you a better idea of whether it would actually work as well as point you towards someone who could do it if you don't have the appropriate tools yourself.
     
  3. loz_the_guru

    loz_the_guru
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    That's a really detailed and helpful response, thanks!

    The cable i'm using is one which came with the PSU and not some random ebay jobby. It's 6 pin at one end, 8 pin at the other. The 6 pin end fits into the black port just fine, but has a red connector as opposed to a black one. If used this way, I would essentially be connecting the 8 pin end to the 6 pin GFX card, just with 2 of the ports not powering anything (if this makes sense). Is this a bad idea?
     
  4. EndlessWaves

    EndlessWaves
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    You're talking about PSU 8-pin connector to PCI-E 6-pin connector? I did notice that the ports on the PSU seemed not to be keyed to reject the PCI-E connectors.

    I suspect it's a design flaw rather than intentional. The PSU end looks like it's keyed like an EPS 12V cable, in which case you won't be able to plug it into the graphics card (but could still plug it into the motherboard, with disastrous results).

    The pins on the sticker are different voltages and arrangement to the pins on the PCI-E 6-pin plug so unless the manual says something about using the cables that way then I definitely wouldn't do it.
     

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