2 5870s in new 2010 MacPro?

Discussion in 'Mac Pro' started by schulmaster, Sep 20, 2010.

  1. schulmaster macrumors member

    Aug 7, 2010
    I have a new 2010 hexacore Mac Pro. I'm wondering the steps involved in cross-firing two 5870s. power cable splitters etc..
    Does the PSU even have enough wattage to drive two of these?

  2. alust2013 macrumors 601


    Feb 6, 2010
    On the fence
    I think the issue is that two of them won't physically fit in it. There might be issues with power too.
  3. Spanky Deluxe macrumors 601

    Spanky Deluxe

    Mar 17, 2005
    London, UK
    Two of them will definitely fit in but powering them is the problem since there are only two six pin PCIe power cable sockets. You could use SATA to six pin PCIe power cable adapters going from unused drive sleds, optical bay etc but I know some people using this method had stability issues. Others used a second power supply - you can get special ones that go into 5.25" bays and I know some people on here used them with dual 4870s. The risky option is to get two 6 pin PCIe power cable y-splitters. You'd be taking more power from the board's 6 pin connectors than they're rated for but it could be ok. FWIW I used this method with my dual 4870s that I used to have in my Mac Pro and I ran them like that for about 9 months before upgrading without any problems and 5870s are meant to use a little less power than 4870s. Still, you run the risk of blowing the tracers on the board.
  4. schulmaster thread starter macrumors member

    Aug 7, 2010

    Thanks for your quick reply.
    I'm pretty cautious, so the second power supply option sounds the best. Is installation very complicated? Where could I find an installation guide or video?
  5. Cindori macrumors 68040


    Jan 17, 2008

Share This Page