Question Do I have to use two separate PCIe cables to power my RTX 3060 12GB?

[Garen D]

Hi all, I was wondering if I needed to use two separate PCIe cables to power my GPU( ZOTAC GAMING GeForce RTX 3060 AMP White Edition) or If I can get away with only using one. I've seen people saying that its a bad idea to use one, or that its a bad idea to use two because of GPU Sag. I'm trying to avoid using two cables because I want to minimize how many cables my build has for cable management sake. The Corsair RM750(2021) 750w PSU has a PCIe cable that has two 8pin connectors on a single cable so I was thinking about using just one of them to power the RTX 3060 with it's 2 8pin ports. As far as I am aware it should be fine as a couple searches later I think I am good to just use one because I see that some people only use 2 PCIe cables if the TDP of the GPU is 225W-250W. But I just need some peace of mind and to know any potential issues I might face using a single cable or if I should just use two.

TL;DR
Is it a good idea to use a single power cable that has 2 8pin connectors on the RTX 3060 with 2 8pin ports on it?

Build

• Ryzen 9 3900X
• Corsair RM750(2021) 750w PSU
• ZOTAC GAMING GeForce RTX 3060 AMP White Edition

 

[Gaidax]

It's never a good idea to do that. Use 2 separate cables.

PCI-E Slot gives max of 75w.
Single 8-pin cable/PSU connector rated for 150w. Technically it can go a bit higher actually, but you would be going outside the specification.

TDP is not a gospel number, you can't rely on that and basic math from above and your PSU might not be able to handle all that on single cable or your connector might melt or who knows what else may happen... or well it can be just fine.

But, do you really want to take those unnecessary gambles?

 

[punkncat]

As above, when the option is available to use two different PSU cables, it should be taken advantage of. Actually, a good way to keep track of that cable as well.

 

[Joseph_138]

Zotac's AMP edition cards will often draw more than the rated power spec, because they are extreme overclocked editions. If it comes wth two power connectors, then you should use two separate cables. If you try to chain both connectors to a single connector on the power supply, you could overload it and damage the card, the power supply, or both. You can't go by the specs for a reference card when you're dealing with a card that has a hefty overclock. The power consumption will always be higher on the overclocked card.

 

[bill001g]

This is where maybe people that build computers should learn the very basics of electronics.

The number of connectors on the cable means nothing really. If it was that simple I could magically power my whole computer with 1 wire with 20 connectors on it. Then again technically you really do only have 1 connectors powering the whole computer if you consider it only has 1 cable going to the wall outlet.

What is most important is how large the wire. You could have 1 wire that is rated to carry 300 watts of power or you could have 2 thinner wire rated to carry 150 watts each. There is also a limit on how much power the 8 pin plastic plug itself can run but the ones they generally use are also rated to 300 watts.

Problem is there no simple way to see the difference between the size of wires visually. The key difference is the amount of copper metal used in wires. On one of these cables it likely is only a couple cents different but for a power supply manufacture that makes millions of these cables it can add up.

If the power supply company is being honest they will not put 2 connectors on a wire that is only rated to run 150 watts. So you can generally assume that if there are 2 connectors on the end of the wire the wire itself and the connectors on the power supply can deliver the 300 watts without a issue. The problem mostly comes when you buy power supplies from some vendor that you directly shipped from china.

So if you have the option it will always be better to run 2 physical cables. With a single cable you might be at say 80% maximum load...they can actually run a bit more than 300 watts. With 2 cables you now have much more safety margin just in case a cable get damaged in some way and does not really pass all the rated power. In most cases though using a single cable that is properly made will never cause you a issue.