Topic: Dual PSU GPU Mining issues - Anyone doing this successfully? (Read 8499 times)

Finally it works! I followed the advice of disconnecting sata/molex that was used to power my HDD and the add2psu, and instead running a direct molex from the primary psu to the add2psu. 2 GPUs and USB Powered risers on the secondary GPU.  Also on the 2 GPUs powered by the secondary PSU, I replaced the 6pin (2x3) molex to 8 pin cables, with PCIe cables. With all of this the secondary PSU switches on!
Thank you.

At first, I need to say your rig is complete mess.
It means when some connectors passing to each other, it doesn't mean you can connect them together.
Just one question at start, did you tried to power up rig with only two cards?



Have you tried to do this with both psus? To ensure both psus are working?
This is main and basic thing to know. If so, you can continue further.
I was running similar setup 4x r9 280x with two corsairs 750W and 650W connected through add2psu.
Previously it was working with shorted green-black too. This setup was working for me even without powered risers.
And it wasn't necessary to hang some hdd, or dvd-rom to second psu, it was working without that.
So, in your case, I would do this. Unplug all those reduction molex/8pin cables which are powering gpus.
Then straight connect you gpus with 6+2 pcie cables, and I mean plug both sockets to gpu. That cable is builded for that.
I would connect 2gpus per psu for balanced consumption and best efficiency. 860 mobo+gpus+hdd, 760 gpus.
Then unplug that reduction sata/molex which is comming from first psu to add2psu.
Connect this through straight with molex connector, connect it with closer molex.
For power up risers, now you can use those sata/molex reductions, if you don't have enough molexes.
Same in here connect it with closer connector possible. Don't worry you can connect one hdd from one riser.
Connect gpus and risers from same psus. Then turn second psu on, then first on. Press power button,
and if all of your hardware isn't faulty, it should run now. But as you stated before, you said,
that you burned something, it means even if you have proper cabling now, it's not guaranteed it will work.
So try this, and I hope it will help.

Check out OCLink by Antec.  Simplifies the process for you.  I know you can use this feature on any of the platinum rated PSUs by Antec and possibly others.  Seems like most people go 2x 850w but they also have 1000w available if you need it.

I don't know about that video, but i use first psu to powered 3 usb risers and 3 cards, and secont PSU to powered more 3 usb risers and 3 cards, and rig working fine more than a 3 months.

Power Gpu + Riser with same Psu, if you do diferent them this i ill have problems,

All of my 7 rigs are using 3 Psu each, 1 for mobo + hd , and 2 750w for the Gpus

I have a few USB powered risers. I tested it. The +12V is not taken from the motherboard, it is only from the SATA +12 connector. So you can connect it to either main or the secondary PSU.

It might not be your solution but at the very least you should be only using powered USB risers exclusively.

Try to add some old HDD to the 2nd PSU, so it will draw power no matter what happens with the GPU. It worked for me.

I made sure not to cross riser and cards. My secondary PSU is only powering the graphics cards, not the risers. I have two cards connected to the motherboard with no powered risers, and two cards connected to powered risers powered by the primary PSU. I'm not connecting my secondary PSU to the two powered risers because of this warning from BitsBeTrippin' on youtube (https://www.youtube.com/watch?v=xZiWciJLK3o):


Which PSUs (brand + model) are you using for your setup? Thanks.

I have 2 psu rig, and working fine. Try to powering 3 risers and 3 cards with first PSU, and 3:3 with second. Don't cross riser and cards with both PSU's.
Sorry for my bad english, i hope you can understand me.

NOTE: Ensure one PSU is used for the Motherboard and ALL connections (molexs/sata power connections/ & any other non-GPU connections) The Second PSU should be ONLY used for powering the extra graphics cards ONLY, just the 12v rail connections.

DO NOT USE THE SECOND PSU to power any of the risers...this will create a weird loop back through the MB and potentially nuke it.

As far as I know you'd need something like this:

http://www.thermaltake.com/db/products/PSU_Cable/Dual_PSU_24Pin_Adapter/main.jpg

To turn both PSUs on at the same time.