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Dual PCIe 6+2 for SLI Advice/Help needed - Page 2

post #11 of 12
You'll be fine. You're on a single rail, so the power connections are the same, no matter what cable combination you are using.
     
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post #12 of 12
GPU and PSU manufacturers will generally advise a separate strand for each PCI-E connector on a higher power GPU.

Wire gauge itself is probably sufficient. A more likely point of failure is the mating between the wire and the contact pins, or the pin to pin contacts.

This is four pins with about 7-8A of current draw per pin (Seasonic PSU and cable, btw, but could easily happen with any brand):

87197bb3_IMAG0993.jpeg

One pin was probably loose, or otherwise making poor contact. Under high load it heated to the point the insulation and/or plastic connector melted, coating the pin and cutting off contact, which cause the load to be spread between just three pins, until one of those failed, and so on.

A GTX 980 Ti, under the right loads, can pull just as much current as the CPU I was using when I melted that EPS +12v connector. If the connectors and cable are in pristine condition, three of them will handle that current, but if any of those wire strands break, if the pin isn't crimped perfectly to a wire, or if the pins are loose, something like the above could easily happen.

This is why I always try to spread loads out over as many pins/conductors as practical.
Quote:
Originally Posted by Arsenal FC View Post

The reason to my thinking about using the cable was because it came in the box, what other situation would you use a dual 6+2 pcie?

A lower power card, two very low power cards, or when you only have three outputs on the PSU, or three cables left, and need to go to four PCI-E connectors across two GPUs.

I ran a pair of cards with dual 8-pin PCI-E connectors with two separate 8-pin cables going to the first connector on each card and then a dual 6+2pin cable going to the second PCI-E connector on both...because that's all I had room for at the time.
Quote:
Originally Posted by xxicrimsonixx View Post

You'll be fine. You're on a single rail, so the power connections are the same, no matter what cable combination you are using.

Still has three +12v contacts at the PSU end handling nearly all the current drawn by a 980 Ti. That's a far from ideal situation.

You can do it, and most of the time it will be fine at typical loads, but issues are much less likely with separate cables per connector.
Edited by Blameless - 10/9/16 at 8:24pm
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