# How to connect two PSUs?



## GordonFreemanInTheFlesh (Jul 28, 2022)

I know you can get PSU splitters but do they actually make a *"two female 24 pin atx to a single male 24 pin atx adapter"*?
Is what I'm asking even safe?
I'm planning to run two *250w* Pico PSUs in parallel to effectively get *500w*s of power.
_My intention is to build a 1U AIO pc but I hate the loud server PSUs!_


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## 95Viper (Jul 28, 2022)

Adaptermvp Dual PSU Power Supply Extension Cable for ATX Motherboard,Full Copper 24pin Chassis Power Start line,24 pin to 24(20+4) pin,1ft/30cm
BLUEXIN Pro 24 Pin Male to Female Dual PSU Power Supply Cable PC ATX Motherboard Adapter

Amazon search:  two female 24 pin atx to a single male 24 pin atx adapter


Safe?  Maybe, someone who has tried it will answer that.


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## joemama (Jul 29, 2022)

Does the system actually draw that much power from the 24pin? I would expect 1 PSU to be enough for that


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## hat (Jul 29, 2022)

As far as I know, you would have to split the power up. I've never seen anything that lets you combine two 24 pin connectors into one and actually share the load... Usually they just pair the power on signal, which allows the other power supply to run with the first one. 

You could use one to power the 24 pin, and the other to power the CPU, for example. Or one for the 24 pin and CPU and the other for drives and expansion cards that require additional power.


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## johnspack (Jul 29, 2022)

Only thing I know that used to work,  is a second psu to power a 2nd video card.  Back when I ran sli gtx480s....  a 750w psu wasn't enough,  so I tied in an 850w 2nd.
But running them both to the atx power....  not sure I'd try that.


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## Bones (Jul 29, 2022)

I doubt it's possible to do because of the differences in output voltages obtanied from each PSU on a wire-by-wire basis.
Enough output voltage variance could result in a power "Feedback" up one of the wires back to one of the PSU's - *You don't want that*.

Normally it's nothing to worry about but electricity, like water goes where it wants to (Path of least resistance to ground) and_ if going back upstream from where it should go *is easier*_, that's what it's going to do.



95Viper said:


> Adaptermvp Dual PSU Power Supply Extension Cable for ATX Motherboard,Full Copper 24pin Chassis Power Start line,24 pin to 24(20+4) pin,1ft/30cm
> BLUEXIN Pro 24 Pin Male to Female Dual PSU Power Supply Cable PC ATX Motherboard Adapter
> Amazon search:  two female 24 pin atx to a single male 24 pin atx adapter
> 
> ...


What's shown in the links is for powering up two PSU's at the same time, not for actually powering a board at it's ATX connector from two PSU's.
One of the plugs in the pics shows what I expected to see, there is only one or two wires going to one of them, that plug obviously going to the PSU running GPUs, the other PSU running the board per norm.

Same thing is easily accomplished by a wire going from the ground sense wire of one PSU to the other - Done.

I'm wondering why doesn't the OP simply get a 500W PSU or larger period and just use it.
Easier to work with, no need to have anything special in terms of setup and takes up less space too, being it's the one unit instead of two in play.


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## DeathtoGnomes (Jul 29, 2022)

Phanteks has a couple devices too






						Phanteks Innovative Computer Hardware Design
					






					www.phanteks.com
				









						Phanteks Innovative Computer Hardware Design
					






					www.phanteks.com


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## GordonFreemanInTheFlesh (Jul 29, 2022)

Bones said:


> I doubt it's possible to do because of the differences in output voltages obtanied from each PSU on a wire-by-wire basis.
> Enough output voltage variance could result in a power "Feedback" up one of the wires back to one of the PSU's - *You don't want that*.
> 
> Normally it's nothing to worry about but electricity, like water goes where it wants to (Path of least resistance to ground) and_ if going back upstream from where it should go *is easier*_, that's what it's going to do.
> ...


Well it's cheaper this way!
I know there are brands that make quiet-ish 1U PSUs but they are expensive.



DeathtoGnomes said:


> Phanteks has a couple devices too
> 
> 
> 
> ...


Ok this is nice but it only works for atx 8pin and 24pin lol what about 8pin Pcie?
I think I am going to go with the 2wire adapter from amazon and use one psu to power the Mobo Nd cpu and the other gpu.



Bones said:


> I doubt it's possible to do because of the differences in output voltages obtanied from each PSU on a wire-by-wire basis.
> Enough output voltage variance could result in a power "Feedback" up one of the wires back to one of the PSU's - *You don't want that*.
> 
> Normally it's nothing to worry about but electricity, like water goes where it wants to (Path of least resistance to ground) and_ if going back upstream from where it should go *is easier*_, that's what it's going to do.
> ...


Thank you for explaining stuff especially now that I know voltage feedback is a thing and it's not good!
Anyway I will just get one of those 10$ amazon adapters that only have 2 sense wires.
I think one pico psu per (mobo +cpu) and one for gpu and drives is enaugh



johnspack said:


> Only thing I know that used to work,  is a second psu to power a 2nd video card.  Back when I ran sli gtx480s....  a 750w psu wasn't enough,  so I tied in an 850w 2nd.
> But running them both to the atx power....  not sure I'd try that.


Thank you for the reply!


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## Bones (Jul 29, 2022)

Arbër said:


> *Well it's cheaper this way!*
> I know there are brands that make quiet-ish 1U PSUs but they are expensive.


There is expensive and then there is *expensive.*

Is taking such a risk worth it vs the cost of a singular PSU of capacity to do the job?
*No. *

I understand saving money but there are times you cut your own throat by being too cheap and this is one of them. 
Get a decent unit of needed total wattage capacity and be done with it is the only advice I have from here onward.


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## 1freedude (Jul 29, 2022)

How did you plan on powering the picos?


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## Shrek (Jul 29, 2022)

I've always wondered about balance, if one supply aims for 12.1V and the other 11.9V; at least they won't fight each other.

However, if one supply crowbars, that could be an issue.
What is Crowbar Circuit ? Design and Operation (electricaltechnology.org)


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## GordonFreemanInTheFlesh (Jul 30, 2022)

Bones said:


> There is expensive and then there is *expensive.*
> 
> Is taking such a risk worth it vs the cost of a singular PSU of capacity to do the job?
> *No. *
> ...


Well my requirement is around 1000w and the only PSUs that *fit* inside a *1U* chasis are server psus which lack the 24pin atx connector!
And not forgetting to mention them sounding like jet engines!
I don't mind using external power bricks (in my case 4x10a,12v) for a total of around 950w give or take
Each Pico has 2 DC 3.5mm jacks


http://imgur.com/a/xIxctWv




1freedude said:


> How did you plan on powering the picos?


Via 4, 12v 10a external power bricks!
Since each pico has two 3.5mm DC input jacks.
I don't really mind 4 power bricks in fact i think if you ziptie them together it looks bada**!
Lol
Well my other option is to use an HP1200w server psu in conjuction with one pico but I'd have to replace the PSU fan with one from noctua!



http://imgur.com/a/xIxctWv


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