# Can I use 20 pin PSU in 24 pin motherboard?



## MikeTyson (Dec 15, 2009)

Basically I've just got a PSU of 550W, better than my 480W for the W rating obviously

It's a cheaper generic model but it has come from an OEM SLi system with exactly the same setup as mine other than the motherboard...

The power supply only has 20 pins for connecting to the motherboard, but my motherboard has a 24 pin socket...

Will it be stable if I just plug in this 20 pin power supply to my 24 pin socket?

Thanks


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## [Ion] (Dec 15, 2009)

Yep, it'll work, I ran a 24-pin mobo with a 20-pin PSU for a while


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## MikeTyson (Dec 15, 2009)

Hmm I've been reading around a bit and some people say that it could be unstable due to having to run everything from 1 rail, cos the extra 4 pins were for splitting the rails?

It's all a bit confusing... but considering this PSU has been in a system identical to this other than the motherboard which had a 20 pin, I'm trying to figure out if there could be a problem still, hmmm...


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## Disparia (Dec 15, 2009)

Yes, most likely. There are adapters that will take 20 pin to 24pin, if stability issues occur.

But why switch out your Hiper 480w, that's presumable working, for a generic 550w?


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## MikeTyson (Dec 15, 2009)

Because when I overclock a bit, the system won't boot

This is only after installing the second video card

Prior to having SLi, and only running 1x 7950GT I could clock up to 3.0GHz and be stable

Same story with my memory, if I clock it up to the 1000MHz I had it at before the SLi, the system won't boot

So I assume it's all down to not enough juice


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## Disparia (Dec 15, 2009)

Specs for the Hiper:

+3.3V, 28a.
+5V, 32a.
+12V1, 18a.
+12V2, 16a.
-12V, .8a.
+5Vsb, 2.5a.
3.3+5V Combined, 240w.
12V1+12V2 Combined, 350w.
Total Power 480w.

Could you post the model and/or specs for the 550w? Generics aren't known for supplying a lot of stable 12v.


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## MikeTyson (Dec 15, 2009)

Hmm...

I've put it back to 3.0GHz and 1000MHz but I left the voltages on Auto this time around...

And it's booted with the Hiper 480W

This is strange cos it wasn't doing it earlier


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## erocker (Dec 15, 2009)

Please do not make more than 1 thread on the same subject. Thanks. 

http://forums.techpowerup.com/showthread.php?t=110589


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