x399 Designare Ex Power Connection

I'm not if I should post this in the power supply section or the motherboard section. Mods, please move this if I chose wrong.

I'm finally upgrading my PC and have been out of the loop for quite a while.

When you look at the specs for the motherboard (Gigabyte x399 Designare Ex), it has the following connections

1 x 24-pin ATX main power connector
1 x 8-pin ATX 12V power connector
1 x 4-pin ATX 12V power connector

The 24-pin connector is straight forward, but the 12V connectors are confusing.

I have a Cool Master V1000 power supply from a previous build that uses the 4+4 connector. But this doesn't line up with the 8-pin connector. Interestingly, one of the 4-pin cables does line up with the 1x4-pin connector. The other lines up with half of the 8-pin connector.

I also have a Corsair rm750i that has the 8-pin connector which would fit. But, it does not have a 4-pin cable.

Neither power supply has a connection for both types. What is going on here? Do both need to be connected (the manual doesn't specify)?

If so, since both are just supplying 12v and ground, is there an adapter that could be used? Or do I need a new power supply with both connections?

Wait.. I think I answered it. Comparing the wiring diagram in the manual to the PSU, it's the same (all top pins are +12v and all bottom pins are ground) despite the different shapes. Although the pin shapes are different, it's always a D-shaped pin going into a square-shaped hole so it will fit.

Is the answer just to push harder with the 4+4 to connect into the 8-pin slot? The V1000 has two 4+4 pin connections, so I could power all of them that way.

you use an 8 pin EPS connector and a 4 pin CPU connector.

you never use a 6+2 or 8 pin PCI express connector.

Master_shake_ said:

you use an 8 pin EPS connector and a 4 pin CPU connector.

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Just to clarify what your saying and apply it to my situation. The motherboard has an 8-pin EPS connector, but it can be powered safely using a 4+4 cable, correct?

Since the V1000 has outputs for two 4+4 cables, I would use all the pins of one cable (4+4) to plug into the 8-pin connector. Then run a second 4+4 cable and only use half (4) to power the 4-pin connector leaving the other 4pins unplugged. Does that sound right?

Those are the power cables I just put away when I switched from a Supermicro E3-1270 build to a gaming/consumer build.

I'm using a Seasonic is 860, it came with cables that would accommodate server mobos.

I'm not seeing the right cables for the x399 Mobo listed with your PSUs.

somebrains said:

Those are the power cables I just put away when I switched from a Supermicro E3-1270 build to a gaming/consumer build.

I'm using a Seasonic is 860, it came with cables that would accommodate server mobos.

I'm not seeing the right cables for the x399 Mobo listed with your PSUs.

Click to expand...

I looked at the Seasonic 860. It lists 1 x EPS12V / ATX12V 4+4 Pin Connector. Are they used interchangably?


The motherboard never actually refers to anything as EPS12V, only ATX_12V_1 and ATX_12V_2.
Here's the manual: http://download.gigabyte.us/FileList/Manual/mb_manual_x399-designare-ex_e.pdf

Look at page 25.

I have different connectors that have sat unused, depending on whether I'm using a server or desktop board.

Contact your PSU vendor and see if they'll send you out some cables.

dpow7 said:

Since the V1000 has outputs for two 4+4 cables, I would use all the pins of one cable (4+4) to plug into the 8-pin connector. Then run a second 4+4 cable and only use half (4) to power the 4-pin connector leaving the other 4pins unplugged. Does that sound right?

Click to expand...

Yes.

somebrains said:

I have different connectors that have sat unused, depending on whether I'm using a server or desktop board.

Contact your PSU vendor and see if they'll send you out some cables.

Click to expand...

I think that's where we got confused. It's not actually a server board. It's still ATX standard. Thanks for the help anyway!

blackacidevil said:

Yes.

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Thank you. I found another site explaining the 4+4 pin connector which also confirmed my belief. The shapes not matching up threw me for a loop. The +12V and grounds all line up though.

dpow7 said:

I think that's where we got confused. It's not actually a server board. It's still ATX standard. Thanks for the help anyway!


Thank you. I found another site explaining the 4+4 pin connector which also confirmed my belief. The shapes not matching up threw me for a loop. The +12V and grounds all line up though.

Click to expand...

On mine the 8-pin you need is a solid connector.
They're keyed, so pushing hard is what they're trying to stop people from doing.

somebrains said:

On mine the 8-pin you need is a solid connector.
They're keyed, so pushing hard is what they're trying to stop people from doing.

Click to expand...

These things are so hard to explain without pictures. What I have is keyed also, but they are designed to be backwards compatible with 4-pin connectors. All the ones which don't line up are D shaped on the cable and square on the motherboard. A D shaped pin will go into a square shaped hole.

This does a good job of explaining it: http://www.playtool.com/pages/psuconnectors/connectors.html#eps4plus4

I totally know what you are talking about.

I had to swap cables when I did an update build last week.

Luckily I kept the cable bag around.

If you are confident in your EE skills you can make a cabl out of a sleeved harness and a plug.

A lot of guys used to do that when sleeved cables started to become a thing.

Cut your harnesses to length, terminate as you need.

Why buy a $$$ pack if you won't use it all?