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Power connector to the motherboard new build question (need help)

shogun94
Level 7
I am doing a new build and have a question about a power supply hookup to the motherboard.

The MB is a Asus ROG Crosshair VIII Hero (WI-FI)
The PS is a EVGA SuperNOVA 850 P2, 80+ PLATINUM 850W , Fully Modular Power supply.

The question I have is hooking up the power supply to the CPU power on the motherboard. The Asus has a 4 pin and a 8 pin connector but the EVGA only has a 4 pin connectors on the CPU cables..

https://dlcdnets.asus.com/pub/ASUS/mb/SocketAM4/ROG_CROSSHAIR_VIII_HERO_WI-FI/E15378_ROG_CROSSHAIR_V...


The connectors say power connectors see section 10 on page 39/110
the connectors are EATX12V_2 (4 pin) and EATX12V_1 (8 pin).

The EVGA power supply has the 4 pin connectors on the end of the cables but not a 8 pin connector. Should I use a 4 pin from the EVGA to the 4 pin on the motherboard and also plug the other 4 pin from the EVGA to the 8 pin on the motherboard? I actually plugged in the 4 pin cable to the 8 pin on connector on the motherboard and it fits where the 4 ping is justified to the pin 1 on the 8 pin connector but I have not applied power yet in fear I may damage it.


You can see a picture of the EVGA cable here, they are labeled CPU.

https://www.evga.com/products/product.aspx?pn=220-p2-0850-x1#images-3


What is the recommend way to do this?
Thanks
DB
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8 REPLIES 8

Falkentyne
Level 12
It's an 8 pin simply split into two 4's. Just use both of them. This is done for convenience as well as compatibility reasons with older boards that only have a 4 pin. Otherwise you would have to "hang" 4 pins of an 8 pin EPS12v over the 4 missing pins.

It's becoming a common trend now to simply have the 8 pin detached into two fours, instead of having them all molded into one housing. The drawback of this is it makes inserting them a bit more annoying, especially with lack of space....

I'm going to try to draw this in text so hopefully it will make sense.

The normal 4 pin is like this:


The image in the motherboard shows the pins look the the following
S = the shape in the connector around the pin is Square
HR = the shape in the connector around the pin is Half round . It shows square on top and round on the bottom


----------
| S | HR |
|HR | S |
----------


----------------------
|HR | S | S | HR |
| S | HR |HR | S |
----------------------


I tried to attach a picture to show the connector but the connector looks to be keyed in a way such that I can plug one 4 pin from the power supply into the 8 pin but only if it's right justified in the 8 pin connector.

FYI,
I did use a second "CPU" cable from the power supply and it plugged in so the CPU power connectors on the Motherboard are fully populated.
Thanks,
DB

DeadlyMercury
Level 7
Could you show a picture how you did that?
As said above, your 4pin cpu power cable is actually 4pin+4pin, so you should use 2 calbes and one cable for 8pin and other for 4pin - but not connecting 1 cable to both plugs plus adding missing 4pin to 8pin plug.

So just to confirm for others in the same situation, PSU connected to CPU power looks like [(88)][88(88)] where the [88] is a 4pin and [8888] is an 8pin, and (88) are the inserted 4pin connectors (4+4 pin)
This should be a safe way to run a 4+4pin psu connector into 8+4pin cpu power on motherboard using stock settings, no 24/7 OC?

Antec eg550 80+ Gold
Rog Strix x570 e
ryzen 7 3700x
gtx 1650 super sc
corsair vengeance lpx 32gb ram
samsung evo 860 250gb

Here is a picture.

I use 2 CPU power cable where each has 2 four pin connectors on each end.

The first CPU cable from the PS comes up on the left and is shown in RED. It plugs in the right 1/2 of the 8 pin connector and also the 4 pin CPU power connector.

The Second CPU power cable comes in from the right and is shown in yellow. One of the 4 pin connectors is plugged into the "left side of the 8 pin connector and the other 4 pin connector from the PSU is unused. and in hanging down and to the left.

The white shows the motherboard where the 4 pin connector on the left and the 8 pin on the right on the motherboard.

DB

DeadlyMercury
Level 7
Well, you did as I was afraid of 🙂
I don't think that will actually harm your pc because there is only ground and 12v and I think your PSU have single 12v bus, so no matter of how to connect it.

But actually you need to connect 1 wire to 8 pin (both 4+4 pins must be connected from single wire to single 8pin connector) and other half of wire to 4pin.
In your case you could disconnect red wire from 8pin and insert not used 4pin from yellow wire. They should be fine since they designed to do so.

Like this:
84922

OK, I understand and made the change as you suggested . Thank you for the advice.!
DB