New build and not enough cables?

[Fkoulou80]

Hi all,
I’m at the end of a build but running into a problem. Not enough 8pin cables.
I’m using
Aorus elite ax ddr4 mobo
32gb 3600 ram
13700k (likely going to undervolt it)
240 aio
Evga 3080ti
850w psu
The psu came with only 4 8pin cables. The cpu has two 8pin connections on the mono and the gpu has 3. Am I able to get away with only one cable going to the cpu or do I need a new psu?
Thanks in advance.

 

[Norton]

motherboard 8 pin and gpu pcie 8 pin cables are completely different- read the manual. What model/brand psu is it and is it new?

 

[Hyderz]

motherboard 8 pin and gpu pcie 8 pin cables are completely different- read the manual. What model/brand psu is it and is it new?

was going to say... it should be different to gpu cables...

 

[Fkoulou80]

motherboard 8 pin and gpu pcie 8 pin cables are completely different- read the manual. What model/brand psu is it and is it new?

Cooler master mwe 850

was going to say... it should be different to gpu cables...

Shoot. Thank you.I’ll have to double check tomorrow but I believe there were actually interchangeable

 

[Norton]

Cooler master mwe 850


Shoot. Thank you.I’ll have to double check tomorrow but I believe there were actually interchangeable

See list from your psu- the 6+2 cables are for the graphics card EPS 4+4 and EPS 8 pin for motherboard (second pic (purple) is your cable layout)

 

[Fkoulou80]

See list from your psu- the 6+2 cables are for the graphics card EPS 4+4 and EPS 8 pin for motherboard

View attachment 289647

I’m crashing for the night so I’ll check first thing in the AM. I don’t think I have 4x 6+2. Keep y’all posted!

 

[Deleted member 223428]

I’m crashing for the night so I’ll check first thing in the AM. I don’t think I have 4x 6+2. Keep y’all posted!

Accroding to the diagram that @Norton posted, they're probably two cables with a pair of 6+2 pin connectors per cable.

 

[joemama]

Shoot. Thank you.I’ll have to double check tomorrow but I believe there were actually interchangeable

The plugs on the mobo side are not interchangeable, if it doesn't fit then don't force it in

 

[Fkoulou80]

See list from your psu- the 6+2 cables are for the graphics card EPS 4+4 and EPS 8 pin for motherboard (second pic (purple) is your cable layout)

View attachment 289647

So based on what i had going to the CPU it was a 4x4 that said CPU and an 8pin that noted CM-PSU. unfortunately I did think all 8's were built the same but should I just be going with the 4x4 to the CPU?

 

[GerKNG]

The cpu has two 8pin connections

there is no reason to plug in more than one.
one 8 pin alone is already rated for 336W and can deliver ~400W if it's a decent PSU/Mobo. so you can't even max one 8 Pin out.

 

[Fkoulou80]

there is no reason to plug in more than one.
one 8 pin alone is already rated for 336W and can deliver ~400W if it's a decent PSU/Mobo. so you can't even max one 8 Pin out.

BOOOM!!! that's what i was hoping to hear
However, does that mean the cable marked CM-PSU can be used as the third 8pin for the GPU?

 

[GerKNG]

BOOOM!!! that's what i was hoping to hear
However, does that mean the cable marked CM-PSU can be used as the third 8pin for the GPU?

No.
they have a different layout.
CPU Powercables are only for the EPS 4/8 Pin on your motherboard.

 

[Fkoulou80]

No.
they have a different layout.
CPU Powercables are only for the EPS 4/8 Pin on your motherboard.

Ok...so I then have the one 4x4 CPU cable and the 8 pin CM-PSU cable dedicated for the CPU
The PSU has 5 identical slots labeled 8P PCIE/CPU though...Yet only 4 8pin cables with two of those marked as CPU.

Looking like I need a new PSU Glad this all came up before powering it on and frying my GPU lol

Thank you all for you help!

 

[GerKNG]

The Pinout is on the PSU proprietary. (that's why you cant mix cables from different PSUs.)
the Pinout on your Motherboard and GPU is completely different.
you need a new PSU in this case. (the Corsair RM###X Shift series is actually ATX 3.0 specced and a good investment for the future)

 

[Norton]

If you don't have the 6+2 pcie cables you should be able to order replacements from CM or custom ones from a variety of vendors. Note that in the case of your psu the cables are interchangeable on the power supply end but the opposite end they are not.

This is what the gpu end of the pcie 6+2 cable looks like

 

[Fkoulou80]

You've all been a great help. I've packed up the PSU for return and looking to go with a Corsair RMx Series RM1000x. It's a refurb but hopefully not complete dog doo to work for me Starting to think 850w is cutting things a bit too close just in case there's a power spike.

​

 

[Hyderz]

You've all been a great help. I've packed up the PSU for return and looking to go with a Corsair RMx Series RM1000x. It's a refurb but hopefully not complete dog doo to work for me Starting to think 850w is cutting things a bit too close just in case there's a power spike.

​

850w is fine for 3080ti, i have a 850w psu running 3090

 

[oxrufiioxo]

850w is fine for 3080ti, i have a 850w psu running 3090

I think this it too generalized my 3080ti worked fine with 1 out of 5 850w psu all seemingly high quality units from corsair, evga, seasonic triggered protections with them.... I tested a pny 3090 that worked fine with all of them in the same scenario that was triggering protections. My theory is with the 3090 a larger portion of it's power budget is going to the memory making transient spikes less of an issue some pcb might also have better transients due to being higher quality.

It also worked fine in only 1 out of 3 750w units although the one it worked fine in was the SFF platinum rated Corsair unit.

Maybe my FTW3 is just special but it's sitting in a pc right now with a newer 850w Prime TX and working just fine where as with an older prime ultra titanium from around 2017 it tripped protections as well.

 

[Fkoulou80]

I think this it too generalized my 3080ti worked fine with 1 out of 5 850w psu all seemingly high quality units from corsair, evga, seasonic triggered protections with them.... I tested a pny 3090 that worked fine with all of them in the same scenario that was triggering protections. My theory is with the 3090 a larger portion of it's power budget is going to the memory making transient spikes less of an issue some pcb might also have better transients due to being higher quality.

It also worked fine in only 1 out of 3 750w units although the one it worked fine in was the SFF platinum rated Corsair unit.

Maybe my FTW3 is just special but it's sitting in a pc right now with a newer 850w Prime TX and working just fine where as with an older prime ultra titanium from around 2017 it tripped protections as well.

In your 850W Prime, do you have the FTW3 "fully cabled"? I mean do you have 3 individual 8pin cables going to the card? I'd be ok leaving an 8pin bay for the CPU open but i feel sketched out leaving one empty on the GPU. The PSU i had only came with 2 PCIE cables :|

Would you suggest in fact going up to a 1000w PSU?

 

[oxrufiioxo]

In your 850W Prime, do you have the FTW3 "fully cabled"? I mean do you have 3 individual 8pin cables going to the card? I'd be ok leaving an 8pin bay for the CPU open but i feel sketched out leaving one empty on the GPU. The PSU i had only came with 2 PCIE cables :|

Would you suggest in fact going up to a 1000w PSU?

Yes it comes with only dedicated 8 to 6+2 pin pcie cables not those terrible daisy chained ones. Definitely never use a high end gpu unless you have enough distinct pcie cables to power it never use daisy chained cables on a high end gpu.

 

[Fkoulou80]

Yes it comes with only dedicated 8 to 6+2 pin pcie cables not those terrible daisy chained ones. Definitely never use a high end gpu unless you have enough distinct pcie cables to power it never use daisy chained cables on a high end gpu.


View attachment 289703

That's where my problem was with the PSU i got. Didn't think about it and now the build is delayed until i get a new one. C'est la vie
Thank you all again for your time with this one. This is what happens when I build a system every 5 or so years and assume i know what's going on lol

 

[Fkoulou80]

Folks it looks like I have another question with my NEW 1000w psu. There are 2x 8-6+2 cables, then a PCIE single 12 pin to two 6+2 pin ends (see image). Why can't this be easy lol I could have sworn there were 3x 8-6+2. How do I use this to power the 3 8pin slots on the GPU?

 

[Ruru]

Those 12+4 pins are only for newer Nvidia cards. If your card doesn't have that connector, you don't need that cable and just use those "classic" PCIe cables.

edit: Read your post again. Are you sure that it has only 2x 6+2 pin cables?

 

[maxfly]

Folks it looks like I have another question with my NEW 1000w psu. There are 2x 8-6+2 cables, then a PCIE single 12 pin to two 6+2 pin ends (see image). Why can't this be easy lol I could have sworn there were 3x 8-6+2. How do I use this to power the 3 8pin slots on the GPU?
View attachment 289876

Use the two individual 6+2 and one of the ones in the picture.

 

[Fkoulou80]

Those 12+4 pins are only for newer Nvidia cards. If your card doesn't have that connector, you don't need that cable and just use those "classic" PCIe cables.

edit: Read your post again. Are you sure that it has only 2x 6+2 pin cables

That is 1 cable going from the 12pin to the two 6+2. I think @maxfly got it though. It makes the most sense

Thanks