How to run 2 PSu at the same time??

sashin

New member
Guys i don't post here too much so forgive me if this has been answered in the past. I have a Mach 2 GT (r507) with 2 7800GTX in SLi , DFI NF4 DR mobo, Koolance Exos 2 (still not hooked up to the graphic cards yet), AMD Athlon 64 4800+, 5 hard-drives and 3 optical drives and a couple of CC lights. I intend to overclock the hell out of my graphic cards (currently running BFG OC at 490 core and 1315 memory on standard heatsink and fan) and from reading through the web these babies drains about 275 watts of power per card when overclocked. My current PSU is the Enermax 600watts which powers the whole thing at present. That is roughly a total of 550 watts for just the graphic cards!! and i still have a whole bunch of other components that are draining power. I also have another Enermax 480 watts PSU just lying around and i am thinking of TEC cooling the graphic cards alone with the Koolance Exos.

HERE IS MY QUESTION...HOW DO I RIG THE SYSTEM UP SO THAT I CAN RUN 2 PSU AT THE SAME TIME. SUCH THAT THEY BOTH START UP AND SHUT DOWN AT THE SAME TIME. It can be done right now just by shorting pin 2 and 4 or something like that in the ATX connector of the 2nd PSU and turning on the power supply to this unit.....BUT this is troublesome as i have turn turn on my main unit and the second PSU everytime i turn on the PC. I intend to use the 2nd PSU to power the TEC units of 80 watts each ...so total of 160 watts and the other remaining components like optical drives, hard discs, lights and fans and such.

I have read that there are ATX splitters that will do this job BUT i can't find them...anyone have any ideas or where to get these cable?

This must be the longest post ever in this forum!!

Thanks in advance.

Sash
 
Hey! That is ONE HELL of a rig you got goin on there :)

About the PSUs... the PSU that connects to the mobo should have taps taken from the green wire and any black (ground) wire to the same pins on the other PSU. YOu can buy in PSU extension looms and mod them so you dont have to cut the wires on the actual PSU. If you can remove about a cm of the colour sleeve from each wire and solder on the connection wires then use heatshrink/electricians tape to stop any shorting them do the same on the other PSU, that should do it. Once its done, better trying the PSUs without a load to make sure they both fire up right, but basically its an extension of the wire-short trick you already know :) Thats a quick explanation without pics...if you need more detail I`ll have a couple coffees and post some pics. I`m having a very slow day today :) Extra marks if you can keep the cabling tidy!

Welcome to the forum, I look forward to you ripping up the Bench tables!

Kenny
 
Thanks for the reply..

K404 said:
Hey! That is ONE HELL of a rig you got goin on there
smile.gif


About the PSUs... the PSU that connects to the mobo should have taps taken from the green wire and any black (ground) wire to the same pins on the other PSU. YOu can buy in PSU extension looms and mod them so you dont have to cut the wires on the actual PSU. If you can remove about a cm of the colour sleeve from each wire and solder on the connection wires then use heatshrink/electricians tape to stop any shorting them do the same on the other PSU, that should do it. Once its done, better trying the PSUs without a load to make sure they both fire up right, but basically its an extension of the wire-short trick you already know
smile.gif
Thats a quick explanation without pics...if you need more detail I`ll have a couple coffees and post some pics. I`m having a very slow day today
smile.gif
Extra marks if you can keep the cabling tidy!

Welcome to the forum, I look forward to you ripping up the Bench tables!

Kenny

Hi Kenny, thanks for the reply BUT u r probably going to think i am a n00b BUT what are "PSU extension looms" and what do they look like? and where can i get them? Some piccies would help though m8 if it isn't too much hassle.

If i do this green(primary PSU) to green(secondary PSU) and any black to black respectively the old fashioned way by just cutting the wires and soldering them, i presume that the 2nd ATX power connector from the 2nd PSU just remains unconnected right? Also any particular wires to use or just use normal wires from any old molex connectors that are lying around?

Thanks again in advance.

Sash
 
Some shops sell ATX extension cables (I call them looms coz theres several bundled wires involved) in case the PSU is too far away from the mobo plug to reach..I`ll PM ya a link, coz we cant link to traders on the forums...t`would be a disrespect to the Boss :)

The actual 20/24-pin mobo plug on the 2nd PSU would still be unconnected yes, but the pins would still short fine and start the PSU. You should be able to do it without actually cutting the wires, just slice off a piece of the sleeve to expose the wire underneath. If you buy the entension cables, I guess it doesnt matter if you cut those wires or not.. Old wire from spare molex is absolutely fine



OR



smile.gif
Managed that without extra caffeine!

Kenny
 
I've got a spare psu relay made from 2 atx extensions (I made it without an extraction tool so it's done by soldering and insulating). PM me if you want to buy it. Please bear in mind you shouldn't run graphics cards and motherboards from different PSUs as the slightly different voltages break them. You can use a relay to switch on a seperate PSU to power your drives (and/or pump, pelts or w/e).
 
Cheers Gollum, I did not know that :) I thought the common ground would be enough. I was gonna do exactly that if I got twin PSUs for my rig... :eek:
 
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