PSU to motherboard problems

[MotleyJester]

I have a Asrock x399 taichi motherboard, and my PSU is the EVGA supernova G3 650 watt. The motherboard has two power inputs besides its 8 pin. it has a 6 pin and a 4 pin. My PSU only has one 8 pin cpu output. The cables it came with are a 8 pin to two 4 pin connectors, and a 8pin to 8 pin/6/2 pin connector (it splits at the end and turns into either an 8 pin or a 6 and 2 pin, I dont know the name for it, also not pictured)  I was wondering what cords I should plug in where? I have an extra VGA output on the PSU I can use. I know the install manuals for both have voltage outputs and voltage input amounts, but I cant tell what comes from where on the PSU, and I don't have a clue if the splitting cords splits voltage amounts. (also sorry if I'm mixing up volts and watts if they are separate, an electrical engineer I am not)

[LukeSavenije]

the ones marked cpu in the mobo, the ones marked pci(e) in the gpu

[MotleyJester]

2 minutes ago, LukeSavenije said:

the ones marked cpu in the mobo, the ones marked pci(e) in the gpu

I already installed and plugged in my GPU, my issue is not knowing which cord to plug where, and which connector on the mobo to power, from which PSU output. The x399 taichi has an 16? pin (which Ive already connected), an 8 pin, and a 4 pin power inputs. my PSU has one 8pin output labeled for the cpu (not counting the 16? pin one Ive already connected), and I do not have a cord that goes from that 8 pin, into another 8pin and a 4pin to plug in. I would need two cords, because I have a 8 pin to 4 pin cable and an 8 pin to 8 pin cable. My question is what should be connected to where?

 

so possibilities:

PSU                     CPU

 

CPU1   -->        8pin

VGA2  -->         4pin

 

or

 

CPU1    --> 4 pin

VGA2    -->  8pin

[mariushm]

The video cards will only accept those connectors called pci-e 6+2  or pci-e 8 pin.  You CAN NOT  mix the cables for CPU with the cables for GPU, the order of the wires is different.

 

You have a cable for CPU with 8 pins, which is also called EPS.

You should also have a separate cable for CPU which is made out of two pieces each with 4 pins.  You should be able to combine those two 4 pin connectors into a single 8 pin CPU connector and insert that one in the second 8 pin connector on the motherboard.

 

It may be possible that the two 4 pin connectors don't combine  (but they should, one should "slide" into the other, there should be some "mechanism" to get those two locked together). If  those two 4 pin plugs don't go inside the 8 pin connector for cpu on your motherboard, try to insert just ONE of the two 4 pin plugs into the motherboard.

 

Plug the cable you have in hand in the picture into the CPU1 connector on your power supply - the 8 pin plug that has CPU written on it,  goes in the 8 pin connector on power supply. The two 4 pin pieces can combine together and then go into the motherboard 8 pin connector.

All connectors are KEYED, the holes have special shapes, they're not square. If they plug doesn't enter easily into the motherboard or gpu connector, don't force it.

[Swarlos]

The X399 Taichi takes an 8pin EPS AND a 4pin EPS connection.  The EVGA Supernova G3 650 Watt only comes with one 8pin (4+4) EPS connector.  I think you need a different power supply for that motherboard.  I don't know if the board will run with just the 8pin EPS populated.  

[Swarlos]

You may be able to get an adapter for the 4pin EPS connection. Are you using both your VGA connections?

[MotleyJester]

35 minutes ago, Swarlos said:

You may be able to get an adapter for the 4pin EPS connection. Are you using both your VGA connections?

nope only getting one gpu, and I tried it with just the 8 pin, it seems to work, but turns out my graphics card wont fit with the case I got and the water cooling loop. so i gotta figure that out now.

[Swarlos]

If your VGA2 output is free I would recommend getting an adapter and using that to power the 4pin ATX12V input.  While I said it may work with that 4pin input empty, I don't recommend it.  I don't want you coming back and yelling at me if something goes wrong

[MotleyJester]

2 minutes ago, Swarlos said:

If your VGA2 output is free I would recommend getting an adapter and using that to power the 4pin ATX12V input.  While I said it may work with that 4pin input empty, I don't recommend it.  I don't want you coming back and yelling at me if something goes wrong

in that case what is the name of the cord I should be looking for?

[Swarlos]

1 minute ago, MotleyJester said:

in that case what is the name of the cord I should be looking for?

You want a PCIe to ATX12V cable.