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PC Building

David1980
Adept I

R7800X3D V12 power connection ?

Hi everyone, 

 

im planning to build soon a full new PC gaming rig and i want to go for the R7800X3D.

Now my question is :

my motherboard ( NZXT N7 B650e ) has a 8 + 4 pin V12 power connector. My PSU is a Corsair RM850x (2021 version ) do i need to plug in a 8 pin + a 4 pin connector ( so using both ports ) or is just the 8 pin enough ?

And if i need to use both i need to use 2 cables what row of the ports of the PSU do i need to use if i plan also a RTX 4080 with it ?

I am

21195104.jpg

a little bit confused about it.

41fllCa1MVL._AC_ (1).jpg

 

8 Replies

Yes, I see that your motherboard has two CPU power ports. One for a 8 Pin and the other for a 4 Pin.

Generally the 8 Pin CPU needs to be plugged in for the Motherboard to boot up. The 4 pin is needed if you plan to overclock your processor which would need more power.

To be safe, if your PSU has a 8 pin and an 4 Pin CPU Power connected I see no harm in connecting both. But the 8 pin CPU power must be connected, at least in the past motherboards.

Also I downloaded your motherboard's CPU SUPPORT list and that processor is not listed, at least not yet:

Screenshot 2023-06-16 152059.png

I noticed the latest BIOS version to download is version 1.24. I would contact NZXT Support and see if the latest BIOS version supports the R7800X3D APU Processor: https://nzxt.com/product/n7-b650e

Otherwise your Motherboard might not recognize the Ryzen 7800X3D processor and not boot up.

Thnx for the reply!

since nzxt BIOS update 1.21 the R7 7800X3D is supported. Nxzt didnt update their lists since...well... 11/11/2022.. Im reading people have the same MoBo and combined with this CPU.

But back to your answer so using just 1 8pin CPU cable on the 8pin port should be enough ? What im reading is that some CPU's only need a 4 pin or an 8 pin.

Using them both is more for extreme overclocking. Cant find on the product page of the 7800X3D what kind of power it needs. Only some gaming benchmarks with total power consumption for the whole system.

In the past most motherboards had either a 6 pin or 8 pin CPU Power port which needed to be connected and in some higher quality motherboards it also included a 4 pin CPU AUX Power port.

As you mentioned, generally, the 4 pin CPU AUX PWR Port is for those that either upgrade to a more powerful CPU or Overclocks the CPU.  The 4 pin adds extra power to the CPU to prevent power issues.

I downloaded your Motherboard's Manual and from my opinion it is a very poor manual. Hardly no explanations for anything. Here is what it says about your Motherboard's ports:

Screenshot 2023-06-16 152934.png

From the Manual's very vague explanation concerning the Power ports I would connect both the 8 Pin and 4 Pin connectors since it doesn't explain if you need both or just one connected. If your PSU doesn't have a extra 4 pin PWR cable you can always purchase a adapter for it.

You can always just plug in the 8 pin CPU PWR cable to the motherboard and see if it boots up and the PC runs without any problems especially power problems. If it doesn't then later on your can connect the 4 pin CPU AUX PWR cable if you want.

Personally your motherboard should run normally with just the 8 pin CPU PWR cable connected like other motherboards. But if it doesn't then connect the 4 pin PWR AUX CPU cable.

As an example only, My Asus Motherboard also comes with a 4 & 8 pin CPU PWR ports. I only have the 8 Pin PWR cable connected since I am not overclocking my CPU.

But my manual stresses that I need to have the 8 pin CPU PWR cable connected for my PC to boot up but not my 4 pin CPU AUX PWR cable (Optional).                                                

johnnyenglish
Grandmaster

We had a similar thread some while ago. The manual should state whats needed. Mine actually says that only one is needed, even when running a monster like 7950X. It also says that plugging both is much better for load balancing, PBO and Overclocking.

I have 8 plus 8 because I've seen in HWiNFO64 some spikes way above what 1x8 can provide.

As for the 7800X3D one should be fine but if you have both, plug them. 

The Englishman

I also have the 7800x3d. My psu came with 2 8 pin to 8 pin connectors. Can I plug 1 in the normal cpu port and plug half (4 pins) of the other 8 pin in the aux port? Or do I need to special order an 8 pin to 4 pin converter?

I plugged both 8 pin plugs in. Works fine. 

0 Likes
Awol
Challenger

The 8 pin on a corsair splits to 2x4 pins, no need for a conversion cable. Plug both into the 2 of the 3 8 pin cpu on the power supply.

BigAl01
Volunteer Moderator

Your Corsair PSU has five 8-pin CPU/PCIe power output ports.  You should be using two CPU/PCIe cables that came with the PSU and plug them into the two CPU power ports on the motherboard.  They are notched / squared to only allow fitting into the proper receptacle on the motherboard.  Four pins won't be connected.  If you cannot get the 8-pin to plug into the 4-pin port due to interference with other motherboard components, then get an adapter cable.

As Albert Einstein said, "I could have done so much more with a Big Al's Computer!".