780GTX in Mac Pro 3.1

Discussion in 'Mac Pro' started by tsaG, Jan 29, 2014.

  1. tsaG macrumors newbie

    Joined:
    Aug 30, 2010
    #1
    Hi,

    Does the Nvidia 780GTX work in my Mac Pro 3.1? If yes, which?
    If was just looking through the specs and found that the 780GTX uses PCIE 3.0 while the 3.1 just has 2.0.

    tsaG
     
  2. superdx macrumors regular

    Joined:
    Jul 23, 2009
    #2
    My 4,1 also only has PCI-E 2.0

    I have a GTX 780 installed on the slot with x16, works fine

    I believe in a 3,1 you can configure which slot uses x16. The 4,1 slots are fixed (two x16 and two x4)
     
  3. flowrider macrumors 601

    flowrider

    Joined:
    Nov 23, 2012
    #3
    No you can't. In a 3,1 the two bottom slots are PCIe 2.0, 16 Lane. The two upper slots are PCIe 1.0, 4 Lane. The configuration of which you speak is possible only on the 1,1 and 2,1 Mac Pro, but those slots are all PCIe 1.0.

    Lou
     
  4. tayh macrumors member

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    Nov 10, 2012
    Location:
    Copenhagen
    #4
    SuperDX how do you power the 780 in your 4.1?
     
  5. superdx macrumors regular

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    Jul 23, 2009
    #5
    I have an FSP Booster X5 installed, there's a number of threads in the forum that discuss it. Just look up "GTX" and threads from Dr. Stealth. Should be informative, with pictures too
     
  6. tayh macrumors member

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    Nov 10, 2012
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    Copenhagen
    #6
    Thanks for the answer.

    I know about the FSP Booster X5, its just not available in Denmark or ebay UK :(
     
  7. superdx macrumors regular

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    Jul 23, 2009
    #7
    There's one or two other makes of a power supply, but I have no idea what they are called. I bought mine off Amazon, and had to get it shipped overseas. Seems they're not in production anymore :(
     
  8. m4v3r1ck macrumors 68020

    m4v3r1ck

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    #8
  9. m4v3r1ck macrumors 68020

    m4v3r1ck

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    #9
    No >450W psu in this format!
     
  10. tsaG thread starter macrumors newbie

    Joined:
    Aug 30, 2010
    #10
    But 450W should be fine since its only consuming 250W.

    So, I have to have such a thing? Powering the Card with the internal 900W PSU will not be possible?

    Right now I have a Ati 6870 and an 3650 installed, works fine.
     
  11. m4v3r1ck macrumors 68020

    m4v3r1ck

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    #11
    Alll depends on how much your system already draws from the 900W psu.
     
  12. riggles, Feb 1, 2014
    Last edited: Feb 1, 2014

    riggles macrumors 6502

    Joined:
    Dec 2, 2013
    #12
    Unfortunately, it's reliant on the power restrictions of the logic board, not so much PSU. The MP only supports up to 225W for any PCIe card, and the 780 can potentially go over it. It's so close, that some go ahead anyway and seem fine because they aren't stressing or over clocking their card. Other gets a flashed card that is slightly modified so it will never draw more than 225W. And some get an aux power supply to supplement the main PSU.

    Edit: Also, be careful of purchasing a new 780. The new ones (780, 780Ti, and Titan) now have the GK110B chips that do not have OpenCL driver support yet and can cause crashing problems in OSX.
     
  13. superdx macrumors regular

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    Jul 23, 2009
    #13
    There were a few threads either on this forum or netkas where people managed to trick the 8pin power connector (short?) to use the Mac Pro built-in 6pin connector. The MP managed to boot up and get into OSX, but under heavy load it probably needed more juice and they got crashes and stuff.

    If you are really on a budget, just buy any GTX 680 PC card with 2x6pin connectors. Works without flashing. You lose the boot screen but you can always get that back by plugging your current Mac video card back in. There's zero functional difference.
     
  14. flowrider macrumors 601

    flowrider

    Joined:
    Nov 23, 2012
    #14
    ^^^^I have a MVC flashed Gigabyte 3 fan over clocked GTX780 (GK110A) in my 5,1. I've been using it now for over 6 months with no issues. And yes, it's been stressed. When the card is stressed the plate under the card gets hot, but when it's not under load the plate is cool. The fans are silent. It's fast and cool but when Nvidia comes out with the new web drivers after 10.9.2 is released I'm expecting a speed increase.

    Lou
     
  15. superdx macrumors regular

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    Jul 23, 2009
    #15
    I didn't see anywhere in the 10.9.2 notes that there were actually new Nvidia drivers, thought it was just the AMD stuff for the nMP.
     
  16. echoout macrumors 6502a

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    Aug 15, 2007
    Location:
    Austin, Texas
    #16
    Wait a couple weeks after the release and see if nVidia updates their web drivers like they've been doing.
     
  17. flowrider macrumors 601

    flowrider

    Joined:
    Nov 23, 2012
    #17
    Actually there are some beta Nvidia Web Drivers floating around on the net. Nothing really useful yet, but there is hope that 10.9.2 will bring new Web drivers from Nvidia.

    Lou
     
  18. m4v3r1ck macrumors 68020

    m4v3r1ck

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    #18
    I asked for a >=500W for using 1 PSU for a SLI config 2x GTX-780 TI... ;)
     

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