Adding a second PSU Corsair 860AX

[dkoc1627]

I will need a total of 1600 Watts and currently own a Corsair 850AX.

Is it possible to add a second 850AX to my system?
How do you take into consideration the power and reset buttons when this is done?
Or, would purchasing a different PSU all together be more beneficial?

The additional power is required to power 4 GPUs.

Thank you.

 

[Someone Somewhere]

What four GPUs?

I believe there are extension cables that go between your motherboard and the ATX cable from the PSU, and take out the 'power on' feed to a separate connector. You need one of those, plus a case that supports two PSUs.

 

[civers1]

Found THIS, but I have absolutely no experience with using one. I would suggest using one PSU for your GPUs and the other for the rest of the system if possible.

@Someone, Would you think that this adapter ties the grounds together in addition to turning the unit on. That way there isn't any risk of bad ground loops, or noise?

 

[Someone Somewhere]

That would do it too, though the second PSU will turn on some time (probably a few hundred ms) after the first.

The PCIe connectors have ground in addition to 12V, so ground is connected through the slots.

I'd run three of the GPUs off one PSU, with the other and the rest of the system on the other PSU. Four fast GPUs can wipe out 800W easily.

 

[dkoc1627]

They are GTX 760s and each require 250W. I like your suggestion on getting a second 860AX and running just three GPUs off that. Even a 750W PSU would work with your suggested configuration.

I saw that "adapter" that civers1 posted; but have no experience using one.

Thanks for your help

 

[Someone Somewhere]

A 750W PSU won't have six PCIe connectors (though you could use peripherals, given there'd be little other load.

 

[civers1]

what I was concerned about is the MB getting +3.3 or +5 signals through the PCIe slots that were coming from a different supply. If the negative side of the circuits are isolated it will cause all kinds of problems with the signals. Voltage could be low, frequencies could be incorrect, bits can be lost all together.
Like I said I have never installed 2 separate power supplies into one computer, but I have installed multiple power supplies on other devices or equipment. And, I have seen many issues arise due to improper grounding, and circuit completion.
@dkoc I am interested to hear how it goes if you decide to give it a try.

 

[dkoc1627]

civers1,

It may be best if I just stick to getting a single 1600W PSU. But, before I make my final decision I'll dig around and see if I can find more info on using 2 PSU in a single machine. I'll let you know what I find.