PSU has only 2 PCIe connectors but RX 9070 XT requires 3

[DarkFury]

Hiya, i'm sorry if this has been asked before but. I bought a Be Quiet Pure Power 12 1200w PSU that only has 2 PCIe connectors but i'm thinking of going for an AMD GPU for the first time but the Gigabyte RX 9070 XT Elite require 3 PCIe connectors. I know they are rated for 150w each and it's something i usually would never do but will I encounter problems if i daisy-chain 1 of the cables?

Thanks.

 

[rare]

Even if it only has two, each cable should have 2x 8 pin connections surely? Although typically it’s not recommended to use the daisy chain PCIE cables in this instance it should be just fine.

 

[DarkFury]

Yeah it came with 2 PCIe cables both have 8pin daisy-chain connectors, i was hoping they are high rated cables so i can daisy chain 1 of them, else i might have to go with a RTX card and use 12HPWR cable instead which I don't mind but was looking forward to an AMD card.

 

[loftie]

Yeah it came with 2 PCIe cables both have 8pin daisy-chain connectors, i was hoping they are high rated cables so i can daisy chain 1 of them, else i might have to go with a RTX card and use 12HPWR cable instead which I don't mind but was looking forward to an AMD card.

IIRC there are a few 9070xt cards that use the 12hpwr. Nitro+ I think it's one.

 

[freddie64]

There is also some 9070XT's that only need 2 x 8 pin.

 

[rare]

Yeah it came with 2 PCIe cables both have 8pin daisy-chain connectors, i was hoping they are high rated cables so i can daisy chain 1 of them, else i might have to go with a RTX card and use 12HPWR cable instead which I don't mind but was looking forward to an AMD card.

I honestly don’t think it will be a problem in this instance. Typically I wouldn’t recommend it but that’s a strong PSU you have, and arguably the third 8 pin on those cards is largely supplemental. I would be shocked if it didn’t work or you ran in to issues with it.

 

[Firegod]

IIRC there are a few 9070xt cards that use the 12hpwr. Nitro+ I think it's one.

Yep and the asrock taichi model.

 

[Jazz2k]

I wouldn't worry about it. Those 8-pin PCIe connectors on the PSU are specced for upto 288w, it's only the GPU side they are limited to 150w.

From the Corsair website (I know you have a be quiet one):
A single 8-pin connector’s maximum current rating is up to, and sometimes more than 24A (288W at 12V). However, the connection at the GPU is only rated for 75W (6-pin) and 150W (8-pin) total for graphics card power.

Daisy chaining them will be fine.

Corsair blog regarding 12vhpw and 12v 2x6 & the 6/8 pin PCIe connectors:

Native 12V-2x6 vs 8-pin to 12V-2x6 – what is the difference?

The difference is purely in the connector on the power supply, but let us take a look at the different ways these can connect to your PSU.

www.corsair.com

 

[Firegod]

Are we sure this is a good idea. I've always said no to daisy chain and AMD and board partners say it has to be separate cables.

Each 8-pin PCIe connector can supply up to 150W. So doesn't that mean that a daisy-chained (pigtailed) cable using a single wire from the PSU to feed two connectors, means you’re potentially drawing up to 300W through one cable if you're feeding two GPU inputs from the same rail.

Doesn't sound good to me. Do the right thing and go with the nitro+ or asrock taichi and use the 12hpwr cable.

 

[Armageus]

Are we sure this is a good idea.

Yes it's fine.

I've always said no to daisy chain

Back in the days of Bitcoin mining and before then, then yes it was a big no. Generally because PSU's weren't as well made, and often with the wrong gauge of cable used for connectors

AMD and board partners say it has to be separate cables.

They would say that, as they have no control over what PSU is being used. It could be a no-name psu with the wrong gauge cable to support both 6+2 power connectors - they have to cover themselves as best they can.

Do the right thing and go with the nitro+ or asrock taichi and use the 12hpwr cable.

12HPWR is never the right thing - it's an absolute bodge that should never have existed

 

[Rogueywon]

Are we sure this is a good idea. I've always said no to daisy chain and AMD and board partners say it has to be separate cables.

Each 8-pin PCIe connector can supply up to 150W. So doesn't that mean that a daisy-chained (pigtailed) cable using a single wire from the PSU to feed two connectors, means you’re potentially drawing up to 300W through one cable if you're feeding two GPU inputs from the same rail.

Doesn't sound good to me. Do the right thing and go with the nitro+ or asrock taichi and use the 12hpwr cable.

Nah, it should be ok in this case. The PSU side connectors can take close to 300W. Daisy chaining is a bad idea when you're running close to the maximum power-draw, but frankly, 3x 8-pin connectors on the GPU is playing it very, very safe for a 9700XT.

 

[rare]

I don’t think you will have a problem at all. I would run it if it were me. Not a big deal.

If you were running a GPU that has 2x 8 pin off a single 8 pin daisy chain connection I would advise against that, but you aren’t…

 

[DarkFury]

Thank you all for your input, much appreciated. If i do go the RX 9070 XT route i think i'll be ok with daisy chaining one of the PCIe and it's is a dual rail PSU so each cable will be on it's own 12v rail anyway.
Cheers again everyone.