nMP GPU Mezzanine Connector

Discussion in 'Mac Pro' started by jonisign, Feb 18, 2016.

  1. jonisign, Feb 18, 2016
    Last edited: Feb 18, 2016

    jonisign macrumors regular

    Joined:
    Jul 7, 2007
    #1
    Hi all,
    Has anyone reverse engineered the nMP GPU mezzanine connector? It would be interesting to know which pins correspond to PCIe signals, DisplayPort, HDMI, and power.

    Thanks!
     
  2. MacVidCards Suspended

    Joined:
    Nov 17, 2008
    Location:
    Hollywood, CA
    #2
    I doubt it will ever happen.

    The cards have more in common with MXM cards as the display outputs are also on there. May also be something connected to the TB2 switches.

    And obviously the PCIE SSD is routed through one.

    They are delicate connectors, when I busted out my Torx Security set and removed them I was impressed by 2 things.

    1. Much more involved and dangerous procedure than taking out a cMP card.

    2. A ham handed idiot could damage those cables and/or connectors.
     
  3. jonisign thread starter macrumors regular

    Joined:
    Jul 7, 2007
    #3
    Right, my google searching hasn't found anyone who has done this.

    In theory, it should be possible to figure this out, and if you did, you could hook up GPU of your choosing into the nMP provided that you pick one that fits and you can line it up with the heat sink.

    This would involve making your own circuit board which pulls in PCIe signals from the PCIe slot on the GPU and DisplayPort signals from the traditional DisplayPorts on the back end of the GPU, and sending them to the mezzanine connector in the right way. Similarly, you'd want to know which pins correspond to power, which you would pull off the mezzanine connector and route up to 6/8 pin PCIe power for the GPU.

    This is no task for the "ham handed" idiot and would be a significant home engineering project.
     
  4. tuxon86 macrumors 65816

    Joined:
    May 22, 2012
    #4
    You would then have to deal with the cooling system that your off the shelf card isn't meant to work with... And in anycase, except for really cheap low power GPUs there isn't any card that would fit in the case except maybe some MXM but those are also hard to get. This would also instantly void any waranty.

    And all this for a machine that isn't really all that popular (in number sold) in the first place.
     
  5. ActionableMango macrumors 604

    ActionableMango

    Joined:
    Sep 21, 2010
    #5
    I will super impressed if you pull this off.
     
  6. Demigod Mac macrumors 6502a

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    Apr 25, 2008
    #6
    Clearly not the most user-friendly standard connectors available.
     
  7. MacVidCards Suspended

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    Nov 17, 2008
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    #7
    Pretty obvious that Apple never intended anyone other than an Apple Certified Parts Swapper from working on them.

    I don't see anyone other than Apple, AMD or Nvidia making these, or adapters to use MXM or external cards.

    Would be amazing if Nvidia decided to offer modern GPUs for 6,1. Imagine if they even included a 2nd PCIE SSD for M2 connection on 2nd card, giving users greater upgrade options. Cupertino would NEVER FORGIVE THEM. Keep in mind Nvidia could do this, they have an MXM version of 980 that is as fast as their desktop reference 980.

    Especially upsetting if they could somehow pipe their HDMI 2.0 support to the built in HDMI. We can dream...
     
  8. flehman macrumors regular

    flehman

    Joined:
    Feb 21, 2015
    #8
    I would like to see this happen for the entertainment value alone.
     
  9. fuchsdh macrumors 6502a

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    Jun 19, 2014
    #9
    Would certainly be a very cool technical feat if you were able to do it.
     
  10. AidenShaw macrumors P6

    AidenShaw

    Joined:
    Feb 8, 2003
    Location:
    The Peninsula
    #10
    There's also the issue that the small power supply on the MP6,1 might have trouble running even one interesting off the shelf GPU.
     
  11. jonisign, Feb 18, 2016
    Last edited: Feb 18, 2016

    jonisign thread starter macrumors regular

    Joined:
    Jul 7, 2007
    #11
    True–– a brief google check says that the D700 is 130W, which is pretty close to the GTX 970's 140W, and definitely enough for the GTX 960 120W. You could probably do dual GTX 970's down clocked a bit and hit the 130W power target just fine. As mentioned, there are MXM versions of the GTX 970 that might fit.

    As for the cooling solution, it looks like there are copper contacts on the heat sink and where the GPU, memory, and power circuitry connect. Not sure what the other black material is around those copper contacts. Is that aluminum, or some kind of plastic?

    Anyways, figuring out the mezzanine connector I/O is the most pressing thing for this project I think. Any one friends with a Mac Pro engineer? :)

    Page 44-45 has the pinouts for MXM:
    www.nvidia.com/object/IO_13290.html
     
  12. Joe The Dragon macrumors 6502

    Joined:
    Jul 26, 2006
    #12
    the pci-e lanes are not there for the 2th SSD
     
  13. MacVidCards Suspended

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    Nov 17, 2008
    Location:
    Hollywood, CA
    #13
    Obviously not, but as Apple was able to oversubscribe the existing lanes for the TB2 ports, could add a PCIE switch for 2nd drive. My second D300 sits for days on end doing nothing, meanwhile requiring 16 PCIE 3.0 lanes. Many better uses for them, like a 2nd drive.
     
  14. jonisign thread starter macrumors regular

    Joined:
    Jul 7, 2007
    #14
    Presumably those PCIe lanes for the SSD could be passed right from the mezzanine connector to the PCB of the GPU to the SDD, without actually touching the logic of the GPU.
     
  15. AidenShaw macrumors P6

    AidenShaw

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    #15
    Actually they are - there are four unused pCIe 2.0 lanes on the PEX in the 6,1.
     
  16. DearthnVader macrumors regular

    DearthnVader

    Joined:
    Dec 17, 2015
    Location:
    Red Springs, NC
    #16
    I hear Apple is going to build a new MacPro with 4 PCIE slots, Thunderbolt 3, USB-C, and offer everyone who bought a MacPro6,1 a trade in program.

    That's more likely to happen than the 6,1 ever getting a GPU upgrade. Face it, Apple decided to build disposable MacPro's, when their space heater AMD cards fail, it will be time to toss them in the recycle bin.
     

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