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RMx 850 PCIe power cables


KeptinAhbveus

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I've never seen PCIe power cables with multiple 8 pin connectors at the GPU end before, so when installing my new RMx 850, I was surprised to discover these. Is it recommended to use a single cable for a 2x 8 pin GPU like a 3070 or 3080, or is it better to use 2 separate cables? And really either way, please explain why if you can.

 

I'd prefer a single cable as it will be cleaner, but if there's a functional benefit to 2 cables (reliability, longevity, stability, whatever), then I'd do that.

 

Thanks!

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I've never seen PCIe power cables with multiple 8 pin connectors at the GPU end before

 

Really? First build in the last 10 years?

 

Is it recommended to use a single cable for a 2x 8 pin GPU like a 3070 or 3080, or is it better to use 2 separate cables?

 

What 3070 or 3080 are you using?

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I've never seen PCIe power cables with multiple 8 pin connectors at the GPU end before, so when installing my new RMx 850, I was surprised to discover these. Is it recommended to use a single cable for a 2x 8 pin GPU like a 3070 or 3080, or is it better to use 2 separate cables? And really either way, please explain why if you can.

 

I'd prefer a single cable as it will be cleaner, but if there's a functional benefit to 2 cables (reliability, longevity, stability, whatever), then I'd do that.

 

Thanks!

 

I asked the same question when going for 2x GPU build with GTX 1070 and RTX 3080 - 2x8 pin version. PCIe standard allows 150W per each 8 pin connection and the cables that come with PSUs are rated for that; the pigtails too for both their connections being fully connected. That means single cable with 2x8 pins is rated for 150W + 150W = 300W itself.

 

The benefit you get boils down to basic physics; you get less resistance and thus more stable voltages, if you use more cables to do the same job. So if you plan to OC and want to get and rely on as stable voltages as you need, you might/will benefit from more cables.

 

You can safely start with lower amount and if you encounter problems, then add more, if you seem to need/benefit from them.

 

My question is below. My use case is 24x7 use (we do Folding@Home during nights) so I wanted to check whether the cabling is OK for sustained high load.

 

https://forum.corsair.com/v3/showthread.php?t=200109

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No, I've done several other builds, but the PSUs I've use did not have the pigtail PCIE power cables.

 

I'll use whatever GPU I can find, but hoping for either ASUS TUF 3080 or EVGA XC3, or even a FE.

 

Most PSUs have pigtail PCIe cables. At least those made in the last 10 years. I mean, unless it's a very low wattage like 450W or something out of a Dell or HP.

 

That's why I'm surprised.

 

If you use an FE, use two separate PCIe cables into the 12-pin adapter dongle. If you use an AIB card, there will be three PCIe and you can use a pigtail for two of those three connectors.

Edited by jonnyguru
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No, I've done several other builds, but the PSUs I've use did not have the pigtail PCIE power cables.

 

Ok. Just found out that in order to use the same PCB and housing for all of the Seasonic Prime PSUs, they give the customer the same number of connectors on all wattages, but the lower wattage 750W and 850W only come with one-to-one PCIe cables. The higher wattage units can, of course, support more PCIe connectors, so they add the pig tail cables to only those higher wattages.

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