Dual PSU How-Tos

[demon-eater]

bump

 

[mcoleg]

why isn't this thread sticky, anyways?

mods? please?

up it goes

 

[stool]

It was a sticky for quite some time, until a mod decided the procedure is dangerous. Quite odd when we have a volt mod section, I think.

 

[mcoleg]

ahh, i see.

live dangerously, die heroically than. don't forget to use real care when playing inside a power supply.

on the other hand, with new vid cards comming out we'll need all the juice we can get. some say one'd need 200W just to run that new nvidia 6XXX card:

http://www.hardocp.com/article.html?art=NjA2

two molex connectors attached to it...

 

[OBLIVIONLORD]

I did the mod and its extreamly easy if you follow the guide on Burnning Issues.com. I dont see how this is a dangerous mod at all since your not touching anything within the PSU's. Your basicly modding the atx extension wiring.

Volt modding is a higher risk then doing this simple mod.

 

[mcoleg]

that's very true, OBLIVIONLORD

i just played with pots inside my new spi 530, now that was scary...

 

[QuantumPC]

Ok, an AT powersupply does NOT require there to be a motherboard for it to run, does it? I mean you flip the I/O switch on the back, and the fan inside spins, and it puts out the juice... correct?


So, what about my 400 watt ATX power supply powering my cpu/mobo/vid card and my 200 watt AT power supply powering my hdd,cd drives, floppy, lights, etc....


Sounds too simple... But i wouldn't imagine you would have to mod either PSU in either way.

Then again I don't really know, so thats why I am asking

 

[RedneckHunter]

This is a GREAT article...took me forever Googlin it.....

I am actually going to ad to the steps by making an external unit. Basically a box with a PSU and 4-5 drives(get some out of my case). My issue is I have a mid tower with 9 drives, 2 cdroms, 8 fans, LED mods, a hoover and a kitchen sink.....

I have a Geforce 5950 ULTRA and it is having some issues these days with not getting enough juice. So I KNOW when I get the 6800 I will NOT have enough juice due to them recommending the card to be on it's OWN rail by itself(needs TWO molex connections). sheeesh I wont mess with trying to run any type of GCard or off the slave PSU, I will use the pri for all that(safer I would think).

 

[GSXR1000]

Hey QuantumPC i was kinda curious about the same thing. Having one power supply into the motherboard cpu and video....and the other for the drives and fan controllers. Is there an safe easy way to do this? How could u get the second one to power on without having it plugged into the mobo?

 

[stool]

Thats basically how I have my rig hooked up. One PSU does the mobo and fan buses(like to have the cooling start with the mobo, so I know its cooled), other does all the drives, lights, etc.

 

[GSXR1000]

Is there anything special you have to do to the second one or can you just connect pin 14 to one of the grounds?

 

[thinksnow]

Trust the Burning Issues acticle.

You can just connect the 14 pin to a ground. You can kind of see it in the top picture:

I tried to make is few permanant changes as possible, still, I reversed the fan in the second PSU to BLOW through the heat sinks, rather than pull through, so it can be positioned the way it is, pushing the inside air out through the PSU out the front of the box. If I didn't have to cut cables or leads, I didn't.

I also cut a notch out next to the original PSU and placed a female plug cobbled from an old PSU, then soldered on a cord so that I could maintain a normal-ish plug on the back for the second PSU inside.

I really should sleeve everything, but the drives are plenty cool with the Stealth 120 blowing over them and the CPU seems chipper enough for now, so I'm not bending over backwards to get to it.


(And no, while the pictures show it sitting on carpet, I didn't do any of the inside work on that stuff. To much risk of static!)

 

[Drizzt1804]

ok i think this was probably already answered but im gonna ask anyway.......i wanna use another case essentialy bolted to the top of my current one as a watercooling box and a way to stick more drives etc. in. All i wanna do is make the extra psu fire up with a relay(not gonna hook it to the moboard).......am i gonna have any grounding issues with this? anything i should be warned about? I just got this Uber arse expensive computer and i realy dont wanna fry it right now so just curious

 

[stool]

Try using the Speedy3d method in the link post. Shpuld take care of what you need.

 

[wicked-one]

Why isn't this a STICKY!? Excellent linkage, stool, I was looking for something like speedy's method.

 

[MadSkillzMan]

what exactly may i ask is the difference between AT and ATX power supplies? I wanted to upgrade to a full tower case in the future since this case is getting really really crammed.

Do you need a special motherboard for an AT PSU?

 

[Baowuf]

what exactly may i ask is the difference between AT and ATX power supplies? I wanted to upgrade to a full tower case in the future since this case is getting really really crammed.

Do you need a special motherboard for an AT PSU?

At the most base level, the AT PSU is for the older (pre-'95ish) motherboards. The ATX is the newer standard.

If you're considering an AT PSU for a dual setup, a newer AT PSU probably has few difference between that and a ATX PSU. You should double check things if you plan on using dissimilar PSU's for a dual PSU setup. Power on methods, output with and without loads, and especially grounding of the PSU.
You would need a AT form factor MB if the AT PSU was your one and only power source.

If you have an option to get a AT or ATX psu, get the ATX. It's the newer standard and it should match the one you have now. (assuming everything else equal)

 

[MadSkillzMan]

ok thank u very much. I was just wondering. I dont have anything pre-95 and thought that AT was stronger for some reason...thanx for clearing that up.

 

[stool]

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[stool]

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