I took one 500 watt psu and another 550 watt psu and hooked up the green and black wires to some hand made molex connectors so that i can hook them up together as a /slave combo or use them as separate psu’s. way when you turn on the pc with the front power button, both of the psu’s will power on and shut off at the same time. I do to power my gfx cards and system fancs on 1 psu and the rest of the pc like mobo, optical/hard drives on another psu.
Kudos for your effort, but wouldn’t it be simpler just to get a 1000w PSU? 
I was able to pick up a EVGA Gold 800w for $60 on sale a few months back, now all I need is a more demanding GPU and I’m all set. 
ps. Moved thread to Off-Topic instead since it is not UE4 related.
I think that’s in case you have a PSU that’s not enough and you can’t afford for a 1000w PSU. ^^
I was one of those people about two years ago. Couldnt run a gtx 460 with a 500W PSU so i had to set exact setup. But it was too crowded for my taste so i gave it up and continued with my 250 until i lost a RAM, which made me get a whole new system by the time UE4 beta began. So yeah, people sometimes need kind of solutions. 
My whole rig is based on these kind of solutions as I might be the only one who is still working with his old LGA 775/DDR2 PC. About time to renew it all just for UE4 some time soon haha.
My system was DDR2 as well, and when i wanted to buy a new 2GB it was more expensive than a 4GB DDR3 - thats where i lost it. And i’m afraid the same thing is going to happen when DDR4 becomes more common… But hey, at least now i’m not on a 15" CRT monitor!(though i miss CRT’s 
)
Yes, but as an engineer I thought to myself "why go buy something when I have the parts/tools and the know how to just do it freely 
? "
Also, im pretty broke, lol. that was a major factor.
ps. thanks you i meant to put in off topic but i failed.
connecting of multiple PSU is quite dangerous thing. Are you sure you did not get some loop current between two of them?
And there is even more risk, if voltage in one of them slightly differs from for eg 4.5V, you connect motherboard to 4.5v one, and graphic card to 4.45v one.
You may get quite nasty current going trough card pcb.
The only thing that’s dangerous about multiple psu is not having them share a common ground, hooking up 2 psus to 1 gfx card, or using that hacky paperclip short mod and not using the signal from the mobo. I have been using systems with dual and triple psu’s for many years running 24/7 for the crypto currency miners, they are still hashing away today. The set up i have is the same exact design as a Lian Li Dual Power Supply Adapter Cable. When i visited Advanced Micro Devices they had multiple pc’s with 4 psu’s and even a few with 6! using the same Power Supply Adapter Cables. They even had a hacky paperclip mod pc running in one of the rooms!
There is nothing dangerous about it if you have it setup right, Riskier ? I guess slightly, since you have now multiple psu’s that could fail. But if you use a proper high energy gfci outlet and a high quality surge protector, there is nothing you need to worry about.
And actually i had an old 500w psu die on one of the miners when it was powering 2 of the gfx cards, when it died nothing happened to any of the other parts, the pc shut down as if there was a power failure, I swapped the psu and then booted, everything started right up, and it was back to mining.
@TheFoyer I love mining crypto.
Man, great idea. I would be to afraid of frying my machine.