Dual Power Supplies?

[CSULB71]

Just curious, but would there be any problems in adding a second power supply unit to my PC in order to split the load? Mobo/cards/RAM on the main PSU and HDD's/optical drives on the second one. I'm not worried about the mechanics of installing it, just whether the whole system would work properly.

[edDV]

No, dual power supplies could be switched to A or B but not run in parallel.

[kush]

Oh really? A simple google search will dispute that...

http://www.google.com/search?hl=en&q=dual+power+supplies&btnG=Google+Search

[edDV]

Oh really? A simple google search will dispute that...

http://www.google.com/search?hl=en&q=dual+power+supplies&btnG=Google+Search

By parallel I meant two voltage pins connected together. I see what they are doing by separately powering subunits like case fans and drives. Just make sure there isn't a voltage short between the two supplies back through the data cable and that ground is continuous.

[kschang]

On the other hand, with 1 KiloWatt PSU's available now, why not get an upgrade?

[rallynavvie]

And I think that 1kW PSU is a PCP&C unit so certainly a quality unit.

Actually you could use seperate power supplies as long as nothing was cross-connected, meaning you weren't plugging in a video card to PSU B when the motherboard is powered by PSU A. There may be issues caused by the frequency of each supply if connected in some way. However I would almost carry this theory over to HDDs and optical drives as well even though the data cable is supposed to be just that: data. You'd also have to use a hard switch for the second PSU as there'd be no way to tie it into the power button on your PC without a lot of work.

I cannot see any reason to attempt this however. If you feel your PSU is inadequate for the task then you should buy a new one that can handle your system all at once. Most users won't need one of the PCP&C 850W or 1000W PSUs unless you're running quad-SLi, two sockets, and tons of 15krpm HDDs. Oh and maybe four burners all going at once. And if you just want to use two PSUs then you could get redundant supplies, they tend to help each other out when the need arises.

[SingSing]

If you know how power supplies work, you can do anything you want. If you have to ask, then you most likely want to aviod messing around with them. You can fried stuff or/and get hurt.

[CSULB71]

I am looking at this as a short-term fix to an older system, using a spare 250W PSU to power my two HDD's and two optical drives. The outputs of the two PSU's would not be cross-connected in any way, so I should be OK. Thanks for the responses and the helpful link.

[normcar]

I believe I would just purchase a good new good from an online dealer, or find one on sale. This is easier, and cheaper compared to destroying your system or burning down a house.

Remember, unless you purchase a new enclosure, the 2nd psu will not have adequate venting to the outside of the enclosure. This could result in higher temps, and shorter lifespans for components.

[zzyzzx]

I am looking at this as a short-term fix to an older system, using a spare 250W PSU to power my two HDD's and two optical drives. The outputs of the two PSU's would not be cross-connected in any way, so I should be OK. Thanks for the responses and the helpful link.

I imagine that you would have to cross connect a ground somewhere. Other than that, if it were somehow externally mounted or a regular AT power supply left out in the open just to power up the hard drives I don't see a problem with it for temporary use.

[ozymango]

If you know how power supplies work, you can do anything you want. If you have to ask, then you most likely want to aviod messing around with them. You can fried stuff or/and get hurt.

AMEN!

Especially the "get hurt" part, there are some nasty capacitors inside those puppies that'll make your hair stand on end (or worse). For the most part, you're not going to hurt anything or anybody by plugging in separate power supplies if you're just powering extra drives -- it's straight DC current to your power taps and it's pretty straight-forward, and I've done this, just because I'm a cheapskate and I've got half a dozen smaller power supplies hanging around, why invest in a new one just to run more drives?

That being said, and with no arrogance intended, I know what I'm doing -- I've been building low and hi voltage circuits since I was a kid and know AC/DC theory down to the ohm. And to make a separate power supply "connect" to your system, you'll need to switch it on/off separately and that involves making internal modifications to the box.

So yeah, if you have to ask, seriously -- don't do it. You can get hurt or, worse, fry your components.

And don't ever let me catch you cutting the grounding pin off your power cords!!! :P

EDIT: As for some of this talk about some kind of electrical weirdness through your data cables caused by overlapping power supplies ... ??? ... dunno if I'm reading people right here, but this is a non-issue. You can demo this non-issue very easily if you have an external USB or Firewire device -- where does it get its power? A separate power supply. There is no connection whatsoever between your power supply and your data channels (aside from electrons zooming around that shared a common mother, the wall outlet). If there is, you've got some serious electrical issues that need fixing!

[CSULB71]

And to make a separate power supply "connect" to your system, you'll need to switch it on/off separately and that involves making internal modifications to the box.

I wasn't going to open the box; I was planning on cutting out the appropriate green and black wires from the 20 pin connector and hooking them up to a separate on-off switch, leaving the PSU plugged in to the AC outlet and its main power switch on.
Thanks again for all the advice -- I'm not certain I'm going to do this yet vs. buying a larger PSU, but I wanted to explore the possibility.

[normcar]

What are you going to tell the insurance company and your family, if your house/apartment burns down. This is the type of thing you hear about someone doing on the news after a fire. If it sounds like a a problem, then it is probably not a good idea. Is it worth $40 -100 to risk a fire, or being fried, or frying your computer? If you answer positive to all the above then do it, if the answer is no, then don't do it. Just because you can do a thing, doesn't mean its a good idea.

[ahhaa]

before starting, check the power draws of your various component units- you may be surprised by where the significant power is being used...

[ahhaa]

ps- a compromise solution: check ebay & your local shops for sexy case deals, there seems to be surplus of them around here... many are on sale for less than the cost of the included hiwatts power supplies.