Troubleshoot PSU for Mining Rig with different GPUs

[Understander]

Hi Everyone!

I’ve been building a mining rig out of my colleague’s spare GPUs and I’ve been strugeling to power it properly. (sometimes it still shuts down unexpectedly)
For now I have 2 x GTX 970, 2 x GTX 1070 and 1 x HD 7950
I’m working with several parallel PSUs (500w + 500w + 300w) but I want to centralize power to better organize the whole system.
What do you guys suggest I should buy?
Keep in mind there are 5 x 8 pin ports, 5 riser cards, 1 x 6 pin ports.
Total wattage of the full set is around 900w.
So far, i’ve searched in a website which gathers some store offers together. I’ll leave the link for the ones I think will do, below.
I’m living in Portugal right now so, I would like to buy it from a Portuguese retailer so that i can claim warranty if anything goes wrong.
If you have any other suggestions (like stores) or recommendations please advise.

Thank you!

My search (sorry for the long URL, query issues): Fontes de Alimentação-Desktops-Servidores-M.Pcs-1300W - 1399W - 1200W - 1299W - 1100W - 1199W - 1000W - 1099W - | Tecmagnet

 

[Digerati]

You are assuming it is power (and it may very well be) but it could also be heat related. So check your temps and if necessary add extra cooling - you might even consider blasting a desk fan on your devices.

One problem I have seen when using multiple power supplies is a lack of a common ground. This commonly happens when different wall outlets are used to supply power to the different power supplies. This happens because every outlet has a different path to Earth ground which means a slightly different resistance to Earth ground through each outlet. So you need to correct this by running a common ground wire between each power supply. It does not have to be anything special. Inexpensive "22awg" wire is fine. Just make sure there are no breaks in the wire and connect it a power supply case screw on the back of each supply, "strapping" each PSU together.

Also, every home and every computer user should have access to a AC Outlet Tester to ensure your outlet is properly wired and grounded. I recommend one with a GFCI (ground fault circuit interrupt) indicator as it can be used to test bathroom and kitchen outlets (outlets near water) too. These testers can be found for your type and voltage outlet, foreign or domestic, (like this one for the UK) at most home improvement stores, or even the electrical department at Wal-Mart. No doubt a local home improvement store will have one for your Portuguese outlets too. Use it to test all the outlets in the home and if a fault is shown, have it fixed by a qualified electrician.

 

[Vasudev]

I'd suggest you get EVGA 1500W PSU or even Rosewill or Seasonic's PSU with beyond 1500W PSU.
Mining can increase the voltage and current to compute/solve the blocks faster.
Which CPU and Mobo are you using?