Mining on the Cheap

edited December 2013 in Hardware support

Greetings, all!

Performed a vivisection on my computer, removing its intestines, in order to put it in a milk crate.  I'm wanting to add another graphics card to my now one card rig.  Running a Cooler Master 500W PSU with one 6-pin pci-e socket and do not have enough separate wire bundles out  of the PSU to adapt to get the four total pci-e connections I need to run two cards.  That's even if this PSU will push both of them.

My question:  can I hook up the 6-pin PCI-e on the second card to a separate PSU?  I'm a  bit cash-strapped right now to buy a proper PSU.

Thanks all.


  • Sure can.  You just need to be sure the PSU is on and already powering the 2nd card before (or at the same time) when the main PSU is on.

    I recommend that you use a PSU with an I/O switch on the back.  Switch it to "O".  Then, close the GREEN and anyBLACK wire at the end of the standard ATX 20/24-pin connector.  You can do this by taking any scrap wire of (somewhat) equal gauge and jam it into the green and (any) black wire end.  When complete, plug in the PSU and flick the switch to "I".  It should power up and stay on as long as that wire closes that loop I mentioned above.  At this point you can turn the PSU off, plug in your 2nd video card, turn the PSU back on, then turn on your PC.

    *I'm not responsible for anything should it smell like burning electronics* 8-)

    Good luck!
  • Thanks falcon.

    Tried it but was defeated, for now.  The 2nd unit worked, it seemed to power the card. 
    Fired up the main power, cgminer didn't pick up the second card.  The 2nd card was listed in Device Manager, but listed with a problem.  The card disappeared when I rescanned. 

    I did make a dummy plug for the 2nd card.

    Tried the 2nd card in slot 0 by itself and it runs great.

    Running on an old Asus sli socket 775 board, Win7, and the v12.8 video drivers for my 5870s.  Didn't think the aging  mobo is the problem.

    I'll take another crack at it in the morning, after I scour the forums for cgminer not picking up 2nd card.  I know I've seen a few posts on that here somewhere.

  • You're welcome, geezer.

    What do you mean when you say "I did make a dummy plug for the 2nd card"?  Does this mean you spliced some stuff together so that the 2nd PSU powers on when the main PSU powers on?
  • Sorry for the delay. No, the dummy plug is a dvi/vga adapter with a few resistors stuck in it, used to simulate a load on the graphic card. I think I read it on the litecoin wiki build tutor page.

    I broke down and bought the bigger PSU, an new evga 650W unit, gold rated. Took it out of the case and put it in a milk crate for better cooling. Everything is working now. Oddly, my vapor-x card doesn't like the second slot. Udder 'n that, my sacrificed gamer is now a respectable and stable little miner, 800 khash.

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