6 pin to 8 pin adapter

Brujah-99

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Jan 7, 2005
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71
I've got an old Corsair HX520W power supply. It's running great, but I'm looking to upgrade my graphics card to something like a GTX1060 or RX580 and both of them require an 8 pin power cable. I have two 6 pin cables that I can plug in to the PSU and get a 6 pin to 8 pin adapter, but I've seen a number of references on other sites to that not being safe. I'm not sure if those other sites were referring to using a single 6 pin to 8 pin adapter or what. Can anyone help me make sense of what might work and be safe? Thanks
 

auntjemima

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Mar 1, 2014
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IIRC an 8 pin offers 150w and a 6 pin 75w. I would think you could get an adapter that goes from double 6, to an 8. Like, a 2 to 1.

Do you ONLY need a single 8 pin or an 8pin AND 6pin for those cards?

ALSO, in my experience, on cards I run for distributed computing, I can power an 8 pin and 6 pin card with 2 6 pins. Technically the pcie slot is 75w and both 6pins are 75w each, effectively giving me 225w. Not many cards out there in the range you are looking at need that much power.
 

ryan_975

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The spec for 6 pin is two +12v lines, two grounds, and a sense. For 8-pin it’s three +12v, three grounds, and two senses.


What nearly every PSU manufacturer actually does for 6-pin is three +12v and three grounds So a single 6 to 8 adapter will be perfectly fine.
 

Tsumi

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What ryan said. As long as you have 6 wires on your 6 pin connector, you're good to go. Theoretically speaking, a 6 wire PCI-E connector can actually handle 200-300 watts.
 

Smoblikat

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May 28, 2020
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6 pin to 8 pin adapters are fine, ive even done dual molex, to 6 pin, to 8 pin.......
 

Tsumi

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6 pin to 8 pin adapters are fine, ive even done dual molex, to 6 pin, to 8 pin.......
Depending on the GPU you're using, dual molex to 8 pin could be asking for trouble. 8 pin can draw more than 150 watts, an amperage of more than 12 amps. If it is on a single molex modular cable, 12 amps exceeds the 8 amp rating of most connectors, which can cause it to overheat and melt the plastic/burn. Depending on the wire gauge used, it can overheat the wire itself and cause the insulation to melt as well.
 

auntjemima

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Depending on the GPU you're using, dual molex to 8 pin could be asking for trouble. 8 pin can draw more than 150 watts, an amperage of more than 12 amps. If it is on a single molex modular cable, 12 amps exceeds the 8 amp rating of most connectors, which can cause it to overheat and melt the plastic/burn. Depending on the wire gauge used, it can overheat the wire itself and cause the insulation to melt as well.
Yeah, been there... more than once.
 

Mchart

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Aug 7, 2004
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You don't even need to buy an adapter if you need to just get it running now. You can easily just ground the extra sense pin to get it running as well.
 

Absalom

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Oct 3, 2007
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Depending on the GPU you're using, dual molex to 8 pin could be asking for trouble. 8 pin can draw more than 150 watts, an amperage of more than 12 amps. If it is on a single molex modular cable, 12 amps exceeds the 8 amp rating of most connectors, which can cause it to overheat and melt the plastic/burn. Depending on the wire gauge used, it can overheat the wire itself and cause the insulation to melt as well.
I'm in the camp that got away with a 6-pin to 8-pin + 6-pin splitter (GTX 670, so around ~150W, fwiw). I even overclocked the GPU.

System with that GPU is still working after 8 years. If it was going to fail, it would have failed within the first year. Granted, the system in question was a Shuttle XPC, so the cables were short. Having short cables does help.

So it's definitely a YMMV.
 

JustinC

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May 25, 2020
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34
JacobParts 6 to 8 pin adapters would work in this case.
I saw them listed on Amazon which means they are in stock so it would not be hard to get in the times of Pandemic.
 
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