Graphics Card in Slot Other than 1 and 2

Discussion in 'Mac Pro' started by cdf, Dec 3, 2016.

  1. cdf macrumors member

    Joined:
    Jul 27, 2012
    #1
    I have a non-flashed EVGA (half-sized, PCI-powered) GTX 750 Ti, which I use to run my 4K display at 60 Hz. I currently have it installed in slot 3 of my 2009 cMP. I understand that there could be a performance hit if the card is not in a 16x slot (and I might have seen some minor screen artifacts), but I rarely use the GPU intensively. The card seems to work fine for my needs.

    My concern is power. My graphics card is rated at 60 W. I know that the 16x slots can provide 75 W each, and I believe that the 4x slots can provide 25 W each. My question is: can the computer's logic board be damaged by having my card installed in slot 3?
     
  2. 666sheep macrumors 68040

    666sheep

    Joined:
    Dec 7, 2009
    Location:
    Poland
  3. cdf thread starter macrumors member

    Joined:
    Jul 27, 2012
    #3
    Would you care to elaborate? Because there is no math here. The card is rated at 60 W. Most of the time it probably needs much less. So I assume that the 25 W of the 4x slot is sufficient. I'm just unsure what might happen when the card needs more than 25 W.
     
  4. chriz_r, Dec 3, 2016
    Last edited: Dec 3, 2016

    chriz_r macrumors member

    chriz_r

    Joined:
    Nov 10, 2016
    #4
    Pcie 2.0 carries 75w in each slots if they're 16x wide. The cards determine how much power they will draw, not the card slot.
     
  5. h9826790 macrumors 604

    h9826790

    Joined:
    Apr 3, 2014
    Location:
    Hong Kong
    #5
    That's a PCIe 2.0 x4 bandwidth slot with the ability to accommodate x16 card physically. In other words, they provide 75W each, but not share 25W for both slot 3 and 4.
     
  6. cdf thread starter macrumors member

    Joined:
    Jul 27, 2012
    #6
    Thanks for your responses. As I understand it, since all the slots are 16x mechanically, they are rated for at least 75 W each. So in my case there would be no problem. In fact, according to the official specifications (support.apple.com/kb/SP506), a slot may even exceed 75 W, because the combined maximum for all of them is 300 W.
     
  7. chriz_r macrumors member

    chriz_r

    Joined:
    Nov 10, 2016
    #7
    Yup. We've had people here run 3 or even 4 GPU setups. The pcie power won't be you're issue.
     

Share This Page