PCIe Cable Power Consumption Question

Faith · 21 Jul 2019

What's up ladies and gents.

I have a question regarding PCIe power consumption for graphics cards. I've searched around and I get a very divided answer to this: Should I use a single power cable with x2 6+2 split on a GPU with slots over 8? or use two seperate 6+2 power cables? I know that the PCIe x16 slot itself give power (75w-ish?), but how much watt does each cable give exactly? I've read that one cable with a split like this is OK for a card that draw less than 215-225w, but I was looking at the Asus ROG RTX 2070 Super card and it has x2 8 slots connectors. The PSU is going to be the Corsair RMx 750w.

Users behind using two cables says it's safer, while users behind one cable says it doesn't matter as long as the card doesn't exceed the total wattage on the cables. I'm not going to overclock. Can anyone share a light to this conundrum? Or maybe share what you're using? All help and info is greatly appreciated. Thanks.

storageman · 21 Jul 2019

I to have had this same problem recently, but with a single slot card. Its a ASRock RX750 8G it only requires 1 slot. In the end after talking to their support, they stated it would not run with just the slot power. I still have no idea what wattage that card draws and they stated I needed to connect it to the power supply. All they cared about was the size of my power supply.

If I was you, I would provide a split connector one for each card to be on the safe side.

Note: I couldn't find a single ended cable in 6+2, so I had to settle on a split one. However I did find out that Corsair power supplies, utilize a different connector for their units vs everybody else. (I have an HXi 850 unit) so when you order your cable make sure its for a Corsair unit.

Dude · 21 Jul 2019

I would use two separate if available. Not sure what the specs are of the PSU, but two 8pins can pull 300watts. I use two separate on my GPU

Faith · 22 Jul 2019

Thanks both.

I will use two seperate cables aswell I think, just to be safe. I will look up the PSU manual. I'm not sure how much watt that Asus card draws tbh.

storageman · 22 Jul 2019

My power supply just doesn't have enough plugs. The only one that was available for a 6+2 connector are the one in circled in RED.

Faith · 22 Jul 2019

storageman said:

My power supply just doesn't have enough plugs. The only one that was available for a 6+2 connector are the one in circled in RED.

You've used up all the others? The HXi 850 have five 8 pin connectors. I only have three, and all will be used. slot 1 for CPU and 2, 3 for GPU with each seperate cable instead of one with a a Y split to be safe.