Would these GeForce 970 & 980 Ti cards work?

Discussion in 'Mac Pro' started by fhturner, Nov 17, 2016.

  1. fhturner macrumors regular

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    Nov 7, 2007
    #1
  2. Synchro3 macrumors 65816

    Synchro3

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    Jan 12, 2014
    #2
    All not overclocked cards with 6 + 6 pin or 6 + 8 pin will work.

    The mentioned MSI GTX 980 Ti with 2 x 8 pin will not work.
     
  3. fhturner thread starter macrumors regular

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    Nov 7, 2007
    #3
    Okay, thanks. Couple of follow-up questions, then: Is the 8+8-pin setup going to potentially draw too much power at "WOT", or is there some other reason it won't work? This card shows a 1000MHz "silent" mode, which would match the clock speed spec on the Nvidia site (is that "reference"?)...could you just keep it in that mode all the time and be alright?

    Thx,
    FT
     
  4. fhturner thread starter macrumors regular

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    #4
  5. ActionableMango macrumors 604

    ActionableMango

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    #5
    Synchro said to stick to a card with 6+6 or 6+8 pin power, and not overclocked. Now you're asking if an overclocked 8+8 will work? o_O

    The limiting factor is the power available in the Mac Pro. There are some janky ways around this, but these are homebrew solutions and not something I'd advise to a client.
     
  6. fhturner thread starter macrumors regular

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    Nov 7, 2007
    #6
    Absolutely, I wouldn't either. I was just looking at the clock rate, which was the same 1000MHz as the Nvidia specs, so I was hoping that this example was not an overclocked one. I got the link from a prior page and pasted it in from my phone...didn't see that table so I didn't realize it was an 8+8, 300W arrangement.

    If you have any suggestions, I'd be most grateful. Okay, so, looking down that list all the way to the bottom is a "vanilla" GTX 980 Ti, it would appear, part #06G-P4-3998-K1. It is 6+8pin, 250W max draw. Is this an acceptable choice and what most folks here would use in their cMPs?

    Thx,
    FT
     
  7. ActionableMango macrumors 604

    ActionableMango

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    Sep 21, 2010
    #7
    Well a lot of people here use 6+8 GTX980ti successfully, but it also draws power beyond spec. So whether that is acceptable or not depends on you and your client I suppose.
     
  8. fhturner thread starter macrumors regular

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    #8
    If we needed, we could draw power from the unused lower optical bay or one of the HD backplane connectors, couldn't we? The PCIe slot and both 6-pin logic board connectors all provide 75W apiece (225W total), correct?
     
  9. ActionableMango macrumors 604

    ActionableMango

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    Sep 21, 2010
    #9
    Yes, that's one of the janky ways around the problem, although I think from prior discussions people were doing two SATA connectors in a Y-arrangement, not just one.

    I'm really the wrong guy to ask. You should just use the forum search for "980ti" for relevant threads and you can read about all the possibilities.
     
  10. chriz_r macrumors member

    chriz_r

    Joined:
    Nov 10, 2016
    #10
    Yup, two sata power (55W each) Y-connector to 6pin PCIe, and then two of the 6pin merge into one 8pin (150w) gives you the useable combo for a 6+8 GPU setup.
     

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