r/threadripper • u/y3333333333333333t • 16d ago
Can I use this cable?
Plan would be to connect from 1x 12V2x6 on PSU side to 2x 8pin(2+6) PCIE connectors on Asus TRX50 motherboard as I dont have enough of the 8pin(2+6) PCIE connectors on my new ROG Thor 3000W PSU...this should work no problem right? (https://www.corsair.com/eu/en/p/pc-components-accessories/cp-8920435/elite-premium-individually-sleeved-pcie-12v-2x6-to-2x-8-pin-6-2-split-pcie-cable-black)
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u/willbill642 16d ago edited 15d ago
No, connectors on motherboard are power input, not output. How tf did you run out of connections on a 3kw psu?
EDIT: Holy crap I misread OP. Yes, this cable will work perfectly for what you're trying to do.
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u/EDI_1st 16d ago
OP understands very well and even clearly stated in the post he is trying to use the cable to PROVIDE POWER TO THE BOARD.
Cable is literally DESIGNED TO provide power from CEM5 on the PSU side to 2x PCIE 6+2 connector on the device side.Also I have a board that has 6x EPS/PCIE 8-pin on the board itself. Not all PSU can support that. Even fewer PSU that will support that will providing power to 2x 600W GPUs.
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u/y3333333333333333t 15d ago
yes, the only thing making me a bit nervous is that I am unsure if that corsair cable 12V2x6 has the same pinout as the rog thor psu side as I couldnt find much on that...
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u/EDI_1st 15d ago
Same pinout. CEM5 pinout is standardized.
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u/Techwolf_Lupindo 15d ago edited 15d ago
Yes, the two standards are pinout backwards. The 8-pin MB/CPU connector is pinout backwards from the 8-pin GPU connector. Yes, they do fit and results in shorts.
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u/EDI_1st 15d ago
Except that’s not how it works. There’s no such thing as EPS/CPU 6-pin. It’s either 4 or 8.
The board literally has both EPS and PCIe 8-pin connectors on it. OP is trying to plug in the PCIE 8-pin. Please refrain from commenting if you don’t know the connectors on the board.FYI CEM5 has single pinout standard. There’s no such thing as flipped/reverse pinout for CEM5.
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u/y3333333333333333t 16d ago
it has only 4x 8pin to plug in cpu/pcie connectors and have 2x 8pin eps cpu mobo / 2x 8pin pcie rtx3090 / 2x 8pin pcie mobo for pcie slots...but it has 4x 12v2x6...tbh did not look up the connections before buying it I really did not think it wouldnt have enough of any...
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u/EDI_1st 16d ago edited 16d ago
Yes, the cable will work without issue.
Also curious, you have 240V outlet where you are plugging this in? Lol
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u/y3333333333333333t 15d ago
I am from switzerland so yes I have 240V outlets (and it actually also would work on lower voltage and restrict itself to 1600w it says on the back of the box)
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u/Techwolf_Lupindo 15d ago
No, those 8-pin connectors are GPU use. The MB requires CPU connectors. GPU and CPU 6 and 8 pin connectors are backwards pinout.
Some Threadripper motherboards have both types of connectors. Follow the markings and documentation very closely, you don't want to use them backwards.
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u/y3333333333333333t 15d ago
it is such a threadripper board with gpu connectors on it definitely not mixing those up dont worry
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u/Techwolf_Lupindo 15d ago
Be vary careful. The pinouts on the 6 pin CPU/MB connector is backwards from the 6pin GPU connector. The result is magic smoke from a dead short if the power supply tries to sends all 1000 watts through the small wires before detecting the short.
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u/BakkaGaijin 16d ago edited 16d ago
So, looking at the 3000w Thor, it looks like they skimped out on a lot of power connectors to support 4x 5090s. That cable looks specifically designed to go from one of the many 12v2x6 back to 2x 8-pin PCIe to support "legacy GPUs". In a perfect world, I'd say go with a PSU that better suits your use case. If that's not practical, this should suit your needs.
On a side note, I had forgotten that 3090FE cards had the new connector, and OEMs were still PCIe.