How does dual PSUs work?

[SomeoneWhoIsntMe]

I've seen cases that can take two PSUs, but I was wondering: how does the second PSU get turned on, and what is it used for?

 

[Pkirk618]

u can usually jump the second PSU by shorting (2) wires...this keeps the PSU on all the time. There are switches that can bridge your current PSU wiring to go on and off with the main system.

 

[Vertigo Acid]

poorly

 

[AreEss]

Typically?
Really, really badly. No +3.3V load, not enough 12V load or no load on the right rail, etcetera. The second PSU's life is dramatically shortened.

I'm still working out how to connect two non-redundants properly. It's not that easy.

 

[btf]

I've been thinking of doing this. My OCZ-520 doesn't seem to have enough juice for my current rig.

I've done the pin trick and the power supply started. My question is there any danger to power one before the other? Do you have to time it perfectly?

I would like to use my OCZ-520 for the mobo and everything except the videocards. I would use an antec 430 for the 2 7800's.

What would happen if the 2 videocards got power before the mobo? Is there any danger to this?

 

[davidhammock200]

I've been thinking of doing this. My OCZ-520 doesn't seem to have enough juice for my current rig.

I've done the pin trick and the power supply started. My question is there any danger to power one before the other? Do you have to time it perfectly?

I would like to use my OCZ-520 for the mobo and everything except the videocards. I would use an antec 430 for the 2 7800's.

What would happen if the 2 videocards got power before the mobo? Is there any danger to this?

The video cards must be powered by the same PSU that powers the mobo, or you risk damaging both.

You can power drives, fans & bling off a second PSU if you like.

Why do you think the OCZ PS 520W is under-powered?
Test like this: http://forums.extremeoverclocking.com/showthread.php?t=137886

GL