PSU Modding

Danny_75

Danny_75

Danny_75

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Joined
19 Oct 2009
Posts
638
Has anyone done or seen a duel PSU mod? Just looking to get some more power but dont want and cant see the need to buy a 1200W one when i have a spare 700 about the house. Can anyone post a link or give me a heads up on some info about it .

Regards Danny
 
It would help in the I could remember the name of the terminals used for the wires that plug into the 4 and 24 connectors of your power supply ( A name for these terminals would be handy). I'd take both power supplys and remove each connector in turn and re-crimping the cables from both power supplies togther so you have a 2 into 1 on each connector this would then double up the output wattage of the supply
 
It is certainly possible, infact the Silverstone TJ07 case comes with a cable that lets you do this, it is just a neater way of doing what those articles state.
 
I'd take both power supplys and remove each connector in turn and re-crimping the cables from both power supplies togther so you have a 2 into 1 on each connector this would then double up the output wattage of the supply
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No it wouldn't. What you'd get is something between blown fuses and a small fire.

If you want to use dual supplies you only connect one of them to the motherboard. The other supply is then switched on by shorting the correct pins in its 20/24 pin connector. There are readymade wiring looms that will achieve this.

You can then spread the 12v/5v load across both supplies.

It’s worth noting that most power supplies need a load across them before they’ll regulate properly.
 
It is very straight forward -
lian li cases that have dual psu accomodation have a simple 'Y' adaptor for the main mobo plug, this is just to switch psu2 on at the same time, you would obviously need to consider load balance across both units..


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Using two psus in this fashion is not really a very good idea. They're likely to disagree slightly on what "ground" is unless they've been connected together internally in such a way that they are forced to agree. If your graphics card has one notion of earth from its peg cables and another from the motherboard I'd expect things to end badly.

I wouldn't be willing to do this, and I'm the stupid ******* pumping water through his psu. Good luck.
 
Given that the 0v outputs, the power supply casing, and the mains earth should be directly connected there shouldn’t be much of an issue.

That said, if someone’s spent enough money on hardware to actually require a 1200W power supply (unlikely IMO) it seems a bit cheap not to buy something suitable to power it.
 
Im by no means a electrical techniciation but anyone who tells me its a bad idea when they're pumping water around a PSU it has to be dangerous
 
i wasnt using anything, just when i upgrade i was wondering if i had to spend lots of money on a BRAND NEW psu :P or if i could spend abit of money on one of equal wattage
 
6th (and 9th) post by Bremen is the correct answer.
The only thing to be careful of is if a component has multiple power inputs (mobo of GFX spring to mind), you can only share those between the 2 (or more) PSUs if the power rails aren't connected. Easily checked with a multimeter.
 
The problem there is that I can't think of a component which only draws power from one place and which uses a lot of power. Graphics cards use one or two peg cables and draw power from the motherboard, up to 75W through the board according to the atx spec. The processor draws most of its power through the 4 or 8 pin atx, but a fair bit from the 24 pin cable as well.

edit: I misread your post I think. I believe you're suggesting that a high resistance between the inputs means it's safe to share the load between two psus. I'm not sure about this, will it not lead to current flowing between the two different 12V lines across the card?
 
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You can buy dedicated supplementary power supplies for video cards for when your primary power supply isn’t sufficient (Google ‘fsp booster’).

They’ve been around for years, so presumably there isn’t too much of an issue with running dual power supplies?
 
JonJ678 said:
edit: I misread your post I think. I believe you're suggesting that a high resistance between the inputs means it's safe to share the load between two psus. I'm not sure about this, will it not lead to current flowing between the two different 12V lines across the card?
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Yes, if there's a high resistance then the rails aren't joined so you can use separate supplies on a mobo or gfx card.
The 6/8 pin PCIe power connectors on gfx cards usually have their 12v separate from the PCIe slot 12v, which is handy :) It actually has to be like this otherwise you can't guarantee where the current will be pulled from.
Same goes for the 4/8 pin and 24 pin ATX connectors, their 12v should be separate (don't have an appropriate board here to verify that).

2 PCIe power connectors on one card may or may not have their 12V separate but I'd assume not if I didn't have a meter to check.

A high resistance would mean a really tiny current could flow between the supplies, but in reality it won't happen because both supplies will be delivering current. It would only happen if you switched one supply off, and it's such a tiny current you'd be hard pressed to measure it. It'd be smaller than the leakage of the output caps in the PSU so you'd not get a voltage buildup.
I could have just said 'no' :)
 
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