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How do i run two psu's?

Discussion in 'General Hardware' started by Humate, 22 Jul 2006.

  1. Humate

    Hitman

    Joined: 23 Dec 2005

    Posts: 652

    I have two PSUs (a 500w and a 600w seasonic). Is there an easy way to use both of them? (my CM stacker can take 2 PSUs). I have done some googling and there is talk of soldering wires and risk of frying stuff, so i thought i would ask. If its gonna be a real hassle i might just buy a 1100w tagan. I bought this 600w seasonic last week without really thinking about it... i just thought i would wack them both in the case and away i go. doh !
     
  2. sugoi

    Gangster

    Joined: 24 Jun 2005

    Posts: 474

    Location: Sussex, UK

    I didn't think any cases would actually support 2 PSU's... but i would do some heavy research before soldering any wires or worse frying stuff, unless you have some confidence and knowledge in doing it... just wondering why you would need such a powerful PSU? :)
     
  3. Humate

    Hitman

    Joined: 23 Dec 2005

    Posts: 652

    I want to fill the case with hard drives (12 eventually) and also have the option of Sli/crossfire. I posted a week back and we came to the conclusion that peak load on startup with that many hard drives might not make a single PSU happy.
     
  4. TheVoice

    Capodecina

    Joined: 15 Aug 2005

    Posts: 21,671

    Location: Glasgow

    You could perhaps have one PSU powering the main system components, and one powering the hard-drives, effectively spreading the load.

    How you could get such a set-up to work properly though, I don't know. There's bound to be a way.
     
  5. paulc

    Associate

    Joined: 5 Oct 2003

    Posts: 78

    Having asked this sort of thing before, I believe the answer is that it is a bad idea. You can have one psu to power your system and another for say a water cooling setup and any lights or mods that are not electrically connected to the system. Just plugging 2 psus into the same system may work, but is probably going to be unstable at best. There might be a way involving soldering and the like, but I think that is going to be very risky.
     
  6. Stelly

    Don

    Joined: 5 Oct 2005

    Posts: 11,043

    Location: Liverpool

    Very bad, unless you busy from a manufacturer that supplys this kind of setup or a board that manages two PSUs... there are a few people that have custom done this but these are electrical engineers, so please do not attempt this!

    Stelly
     
  7. BillytheImpaler

    Man of Honour

    Joined: 2 Aug 2005

    Posts: 8,741

    Location: Cleveland, Ohio, USA

    The original Coolermaster Stacker had provisions for two power supplies. Running multiple PSUs is dirt-common in higher-end kit.

    Humate, what controller(s) are you going to sue for those disks? Many high-end controllers will have a staggered start that eases start-up load on the PSU before the drives' motors produce enough back EMF to lighten the load.
     
    Last edited: 22 Jul 2006
  8. Humate

    Hitman

    Joined: 23 Dec 2005

    Posts: 652

    just motherboard controller... 2 in raid, 2 on IDE, 2 on SATA. But i have more IDE drives i want to stick in the case.

    Buying this 600w seasonic was a mistake then :(
     
  9. BillytheImpaler

    Man of Honour

    Joined: 2 Aug 2005

    Posts: 8,741

    Location: Cleveland, Ohio, USA

    What makes you say it's a mistake? Use the 600W Seasonic for the main system and the RAID array then use the 500W Seasonic for the other drives.
     
  10. Humate

    Hitman

    Joined: 23 Dec 2005

    Posts: 652

    because others in this thread are saying that its a bad idea.

    I have a cable that came with the original 500w PSU that has a female connector running off the 20+4 pin thingy that plugs into the mobo... there are only 2 wires on this connector and they are green and black... what is this connector?
     
  11. Humate

    Hitman

    Joined: 23 Dec 2005

    Posts: 652

    I only mention that cable as Jeantech (the make of the 500w power supply), call this a "20+4 main connector -- 20-pin and 24-pin dual use main connector"... the female connector on the green and black wire could take a male 24 pin connector off another PSU (although i certainly am not gonna try this without knowing what it actually does - DONT WORRY) :D
     
  12. Humate

    Hitman

    Joined: 23 Dec 2005

    Posts: 652

  13. FreeStream

    Capodecina

    Joined: 10 Apr 2004

    Posts: 13,376

    All that does is turn the 2nd PSU on, you cant supply the motherboard using that PSU only HDs/DVD/CD drives.

    CR.
     
  14. Humate

    Hitman

    Joined: 23 Dec 2005

    Posts: 652

    yeh.... but that cable is all i need to run two PSU's right?

    one of the PSUs will plug into the mobo... the other into the female socket on that cable (with the green and black wires) to turn it on at the same time as the other PSU... then i can use the second PSU to power drives??

    im sure thats what this cable must be for... because i have googled and seen people make there own cables out of small bits of wire that look like that cable in the image.
     
  15. FreeStream

    Capodecina

    Joined: 10 Apr 2004

    Posts: 13,376


    THis is how it will be:

    PSU 1 --> ATX Connector --> Spiltter Cable --> Mobo.
    PSU 2 --> ATX Connector --> Splitter Cable.

    Those two wires are the PSUs on switch in effect. :)
     
  16. Humate

    Hitman

    Joined: 23 Dec 2005

    Posts: 652

    I thought so. But i certainly didnt wanna try it before i was certain.

    Then that leaves the only question...

    is it ok to use this cable and run two PSUs? Others thought it was a bad idea but i think this was because of talk about me (a complete and utter electrical retard) contemplating doing some wiring myself hehe.
     
  17. BillytheImpaler

    Man of Honour

    Joined: 2 Aug 2005

    Posts: 8,741

    Location: Cleveland, Ohio, USA

    Well that's what that cable is intended to do. I don't see any problem with it. Be sure to check to be sure all your hard disks are not going to overdraw from the 12V line. The current rating should be on the PSU somewhere.
     
  18. Mr. Brightside

    Wise Guy

    Joined: 27 Apr 2004

    Posts: 2,378

    Yup should work fine, the only thing worth mentioning is that PSUs have a minimum current requirement across the different rails... if you were running just hard drives on one PSU for example this could leave the 3.3v rail unloaded which may not conform to the specs of the PSU. That said, I've used old PSUs before now to power lighting (100w halogen bulbs) at 12v leaving all the other rails unloaded.

    So in short it should work no problems. It seems the only concern when using dual PSUs is the starting up of the secondary and you have that all sorted with your cable there.

    Hope this helps, null :)
     
  19. Humate

    Hitman

    Joined: 23 Dec 2005

    Posts: 652

    ok cool, thanks guys, i will give it a go later :D
     
  20. Imy

    Mobster

    Joined: 21 Nov 2005

    Posts: 2,771

    Location: Nuneaton, UK

    Stability shouldn't be an issue - I've seen servers run up to 3 psu's at a time without problem.

    Your case should have come with this adapter:

    [​IMG]

    Get Coolermaster to send you one if it didn't.

    If you plan to use 12 drives however I recommend you get a decent controller.