Is it okay to power 2 8-pin connectors on a GPU with only one cable with the Be Quiet! Pure Power 11?

[riru]

Hi, I just wanted to make sure that powering a GPU is safe with only one cable with my PSU (Be Quiet! Pure Power 11 700 CM).

I could use 2 cables, but it would be a huge hassle, since I'd have to reorganize some of the cables.

Any advice would be appreciated, thanks!

[Mateyyy]

What graphics card is it?

[riru]

Right now, I only have a GTX 1050Ti placeholder card, but I am asking for preparation for the release of the RTX 3070 cards, since I saw that some AIBs use more than one 8-pin connector. I could try to get a FE, but in my country it's a bit harder to get.

[Kilrah]

If the PSU cable has 2 connectors on it then it's OK to use them both. 

[jj9987]

If you mean one cable, that has two connectors on it - that's fine, it's designed to work like this.

If you mean only connect one 8pin on the GPU - no. The GPU needs more than that.

[riru]

Yes, I am referring to just using one cable that has two connectors. Thanks for the help to all you guys!

[Mateyyy]

13 minutes ago, riru said:

Yes, I am referring to just using one cable that has two connectors. Thanks for the help to all you guys!

Yeah, for a 3070 you should be fine with just a single cable from the PSU. It will pull around 220W, according to Nvidia.

[riru]

That's a relief. Thanks so much!

[riru]

Just to understand things a bit better, a follow-up question:

 

Since my PSU has 2 rails, do I have to worry about my GPU not getting enough power? 

 

Just trying to understand this single rail, multi rail stuff.

[OrionFOTL]

9 minutes ago, riru said:

Just to understand things a bit better, a follow-up question:

 

Since my PSU has 2 rails, do I have to worry about my GPU not getting enough power? 

 

Just trying to understand this single rail, multi rail stuff.

Read your PSU's manual to find out which cables pull power from which rails, and how much power is each 12V rail limited to.

[riru]

Sorry if this is wrong, since I'm new to this kinda thing.

 

From my PSU Manual, it says that 12V1 puts out 36A current while 12V2 puts out 30A, but the total current they can put out is 56A. Combined, the two rails puts out 672W of power.

 

Where do I go from here?

 

[Spotty]

41 minutes ago, riru said:

Where do I go from here?

5. Rail splittings

 

 

[riru]

8 minutes ago, Spotty said:

5. Rail splittings

 

 

Oh I see, I was looking at the wrong part. My bad!

 

My PCIe cable is connected to the 12V1, I believe. It's the one labeled as PCIe 1 on the PSU. Is that good? Do I have to worry about my GPU not getting enough power?

[Kilrah]

Yep, just fine. Most power on a modern PC is taken by the CPU's 4+4 and PCIe, so if CPU is on 12V2 it's good to plug PCIe on 12V1.

[riru]

I see, thanks so much to all of you for helping out! I understand this stuff a bit better now.

 

Cheers

[Spotty]

9 minutes ago, riru said:

My PCIe cable is connected to the 12V1, I believe. It's the one labeled as PCIe 1 on the PSU. Is that good? Do I have to worry about my GPU not getting enough power?

12V1 can provide up to 36A according to the chart you posted from the manual, but it also provides power to the motherboard as well.

If you have issues with the power supply shutting down under load then you might want to try spreading the load over both 12V rails by using 2 cables with one cable on 12V1 and the other on 12V2. 12V2 only provides 30A max and shares with the CPU so ideally you'll want to use 12V1 for the graphics card if using just one cable.

[riru]

7 minutes ago, Spotty said:

12V1 can provide up to 36A according to the chart you posted from the manual, but it also provides power to the motherboard as well.

If you have issues with the power supply shutting down under load then you might want to try spreading the load over both 12V rails by using 2 cables with one cable on 12V1 and the other on 12V2. 12V2 only provides 30A max and shares with the CPU so ideally you'll want to use 12V1 for the graphics card if using just one cable.

I see, that makes sense. I'll just have to test for stability when the card comes in, then. 

 

Just one final question, if I test it with just one cable and the PSU does power off under load, is there any risk of any of my components malfunctioning afterwards?

 

Thanks a lot!

 

P.S. Sorry for the follow up questions, I just wanna take care of my system.