Dual Power Supply Hack
Lazy, Cheap, Ghetto MacGuyverism.
This is my computer.
It eats power supplies. It's got two hard drives, two optical drives, three video cards, PCI sound card, a few fans, it's overclocked through the roof, and it's about as energy-efficient as my truck. A couple of days ago it smoked its fourth power supply.
No big deal, right? Wrong... I had a choice. I could go buy one locally, order one, or use what I've got. It's perilously close to Christmas, and I did not want to go to CompUSA or Best Buy. These are not places I go in December. So I decided I'd order one, and in the meantime I'd disconnect all non-essential hardware and see if I could get by for a few days with a 200 watt unit I had laying around. But this plan was not to be. My spare power brick lasted a mere 20 minutes and then died with much fanfare and a very amusing smell. I did go to CompUSA. Their cheapest PSU was $40 and was only 300 watts. The next step up was about $70 for 400 watts, and there's no way I'm going to pay that when I can go to Newegg and order one for ~$20. Besides, I probably need more than that, because I've killed 400's.
But, this is my COMPUTER. I need it NOW. There is no "wait-a-couple-days." Forget it. So I did what any geek would do and leveraged my network of fellow geeks, all of whom have crap like this spread all over the house just like I do. Nobody had any 400+ watt power supplies though, and I knew I'd need at least that if not more. So one dude suggested two power supplies. I believe he thought he was making a joke, but I didn't take it that way, and so the surgery began. This is the result:
(Yeah, I know. The fan is obstructed. It's okay. Really.) What you see here is a 300 watt ATX power supply from a Gateway ALR7200 server mounted in two drive bays on the left, and a hacked-up, old-school AT brick on the right, mounted where God intended power supplies to mount. The ATX box powers only the motherboard and whatever devices are plugged directly into it, while the AT box powers all the drives and fans. Ample juice to go around.
I did not want two power cords, I didn't want to cut the case up, and I didn't want there to be any possibility of the motherboard being powered up without its devices, or the devices being cut off while the board is on, so the whole thing needed a master power switch and it had to be wired in such a way that the ATX box can't come on without the AT. No problem. The AT brick was modified to use a single-pole switch, and the old switch cord now supplies 110V AC to the unmodified ATX brick by way of insulated spade connectors.
(Pardon my dust.) That's the switch. It's a knob, you pull it out. I think it belongs on a car. One change in the BIOS settings and now when you hit that switch the whole unholy contraption comes to life and boots up.
One cord.
As you can see, there's no outward sign of this blasphemous molestation being present. Just a normal case with some car parts stickers on it. (I had to put the stickers somewhere, and it wasn't gonna be my vehicle. Yeah, I'm an engine geek too.) No Frankensteined growths sticking out except for the unusual switch, no irreversible changes made, in case I ever decide to do the "right thing" and get a properly-rated power supply. It's a cool thing. Nothing spectacular or Slashdot-worthy. I just figured it would come up in conversation a few times and I'd rather do a quick writeup and post some pics than have to take the panels off every time I wanted to show somebody.
I will update this page if the computer ever gets retired, catches fire, kills any hardware, shocks me, melts stuff, or otherwise does anything besides run normally. Until then, you can assume my ghetto-rig was successful.
-DP
drew (at) pittman (dot) ws