My psu has less pins than my mobo. How to connect?

[fael097]

Hey, I bought a rog crosshair vii hero wifi mobo for my good old ryzen 7 1800x, and also an evga 650 p2 psu. Turns out my mobo has an 8 pin and a 4 pin connector for the CPU, besides the standard 24pin, but my psu only has an 8 pin cpu connector and an adapter that makes these 8 pins into 8+8 Pins. It looks just like an Y splitter really. So my question is: should I just connect the 8 pins or should I use the splitter? 

 

And since I'm here, my my gpu is a msi gtx 980ti which has 2x 8 pin connectors but my psu connector is 8+6 pins. Will it work? 

 

I never had this problem, always had low end motherboards that didn't have that much connectors, and an old Corsair 750w psu which had 2x 8pin connectors for the gpu.

[Skiiwee29]

You dont need to use the 4 pin EPS pin for CPU power, the 8 pin is more than adequate for anything and everything when it comes to CPU needs. Your PSU should have 6+2 PCI Graphics cards power plugs, not just a straight up 8 pin or 6 pin. 

[Spotty]

9 minutes ago, fael097 said:

And since I'm here, my my gpu is a msi gtx 980ti which has 2x 8 pin connectors but my psu connector is 8+6 pins. Will it work? 

For the graphics card you will need to use two PCIe cables and use the 6+2pin connector from each cable. The extra 6pin connectors on the cables will just dangle or you can zip tie them back out of the way if you want to keep it looking clean.

 

10 minutes ago, fael097 said:

Turns out my mobo has an 8 pin and a 4 pin connector for the CPU, besides the standard 24pin, but my psu only has an 8 pin cpu connector

Plug in the 8pin (4+4) CPU power connector to the CPU power socket. Leave the additional 4pin empty - it's optional.

[fael097]

Hey, yes, my gpu cable is 6+2 with another 6 pin connector coming out of it. I'm also not sure which of the 8 pin ports on my gpu I should connect which. Let me attach a picture

[fael097]

2 minutes ago, Spotty said:

For the graphics card you will need to use two PCIe cables and use the 6+2pin connector from each cable. The extra 6pin connectors on the cables will just dangle or you can zip tie them back out of the way if you want to keep it looking clean.

 

Plug in the 8pin (4+4) CPU power connector to the CPU power socket. Leave the additional 4pin empty - it's optional.

Thanks! I don't have an extra gpu cable though, my psu has 2x 8 pin GPU slots but it came with only one cable. It was an open box so maybe that's the problem. I have some moles adapters from other systems on my scrapbox though, could it work?

[Firewrath9]

13 minutes ago, Skiiwee29 said:

4 pin EPS pin

Technically, EPS only refers to a 8 pin, ATX is the 4 pin

[mariushm]

2 minutes ago, fael097 said:

I don't have an extra gpu cable though, my psu has 2x 8 pin GPU slots but it came with only one cable. It was an open box so maybe that's the problem. I have some moles adapters from other systems on my scrapbox though, could it work?

Use those two 6+2 connectors if you only have that single cable with the 2 connectors on it.

No, don't use molex adapters to pci-e.

The 980 card  is quite power hungry... with such cards it's always better to have more wires between the power supply and the video card. Ideally you'd want to use two separate cables between the psu and video card, and use only one connector from each cable, in order to have twice the number of wires between psu and video card.

 

A 2 x molex to pci-e 6+2 adapter would be worse..at the very least you'd need to use two separate chains each with molex connectors and plug one molex connector into one chain and the other molex in the second chain ... you'd be making a mess.

 

 

[fael097]

17 minutes ago, mariushm said:

Use those two 6+2 connectors if you only have that single cable with the 2 connectors on it.

No, don't use molex adapters to pci-e.

The 980 card  is quite power hungry... with such cards it's always better to have more wires between the power supply and the video card. Ideally you'd want to use two separate cables between the psu and video card, and use only one connector from each cable, in order to have twice the number of wires between psu and video card.

 

A 2 x molex to pci-e 6+2 adapter would be worse..at the very least you'd need to use two separate chains each with molex connectors and plug one molex connector into one chain and the other molex in the second chain ... you'd be making a mess.

 

 

Problem is my cable is a 6+2 connector and another 6pin only, without the +2. And I don't have another 8 pin cable. So I guess I'll have to buy one?

 

Is there anything I could do just to these this mobo? Just wanted to see if it posts but the r7 has no integrated video, so I needed to connect the gpu somehow, and stores are closed right now, I'd have to wait until tomorrow to get another cable.

 

Can I just connect my gpu to my other psu? 

[mariushm]

Try powering the video card with the 6+2 and 6 and see if it starts.

The extra 2 pins on a 6+2 connect are ground wires, which just tell the video card "this connector is strong enough to give 150w instead of the regular 75w.

The video card may accept and start with just one 6+2 connector.

 

You can get a pci-e 6pin to 6+2 / 8 adapter cable, here's an example: https://www.amazon.com/Cable-Matters-2-Pack-6-Pin-Adapter/dp/B01DV1Z32Y/

 

If the video card won't start with only 6 pin and if you're feeling adventurous you could trick the video card into thinking you inserted an 8 pin connector.

You just need to fake you inserted those 2 wires:

 

 

 

 

[fael097]

1 hour ago, mariushm said:

Try powering the video card with the 6+2 and 6 and see if it starts.

The extra 2 pins on a 6+2 connect are ground wires, which just tell the video card "this connector is strong enough to give 150w instead of the regular 75w.

The video card may accept and start with just one 6+2 connector.

 

You can get a pci-e 6pin to 6+2 / 8 adapter cable, here's an example: https://www.amazon.com/Cable-Matters-2-Pack-6-Pin-Adapter/dp/B01DV1Z32Y/

 

If the video card won't start with only 6 pin and if you're feeling adventurous you could trick the video card into thinking you inserted an 8 pin connector.

You just need to fake you inserted those 2 wires:

 

 

 

 

I have one of these adapters that turns 6 into 8, although one of them is a blank.

 

I was kinda hoping someone would say this is fine and it won't kill my gpu, cause I'm not feeling that adventurous, specially after spending some money on components already, but if it's not safe then I guess I'll just wait until I can get a cable