Windows not seeing GTX 970 on cMP

Discussion in 'Mac Pro' started by robotartfashion, Jun 16, 2015.

  1. robotartfashion macrumors 6502

    Jan 1, 2009
    Phoenix, AZ
    Hey everyone!

    TLDR: GTX 970 works on OSX but not on Windows 8

    I recently upgraded from my 2008 cMP to a 2009 with a 3.33 Hex. It had a gt 120 in it and since I have an unflashed GTX 970 I left that card in and installed the GTX 970 along with it (installed in the first double wide slot). In addition I also have a 4 port USB 3.0 card and the Velocity Duo. My boot drives are on the velocity (osx on one ssd and windows 8 on the other)

    I have two monitors, a 34" uw LG plugged in via display port to the GTX 970 and a older 22" on the gt 120. GT 120 shows the boot screen on OSX, once it loads the GTX 970 is seen (I have the most recent nvidia drivers) without issue.

    When I boot into Windows 8 the GT120 works but the 970 does not. The device manager says that the GTX 970 isn't working properly and so windows stopped it.

    Should I have different drivers than the normal Nvidia ones installed? Do you think the gt120 is creating a conflict?

    I tried searching but can't find any threads to this effect although I thought I remembered something about the 120 creating problems.

    Thanks for any help you can give!
  2. pastrychef macrumors 601


    Sep 15, 2006
    New York City, NY
    When I got my GTX 980, I installed the latest Nvidia drivers from their website and haven't had any issues. I run Windows 8.1 in Bootcamp.
  3. ActionableMango macrumors G3


    Sep 21, 2010
    The 120 and 970 shouldn't conflict. I believe many others keep their old GT120 in for the same purpose you do...boot screens.

    It sounds like a driver issue. My suggestion:
    • In Windows, uninstall all Nvidia drivers (120 and 970) using the normal "Uninstall/Remove Program" process. If there are any issues uninstalling, do a forced removal.
    • Remove the GT 120.
    • Boot into Windows 8.1. Microsoft drivers should provide video, so check here to see if it works.
    • If this works, install the Nvidia 970 drivers and reboot to check to see if it works.
    • If this works, put the 120 back in, and install 120 drivers.
    If you have any steps there that don't work, and you have a spare drive available, I'd try a fresh 8.1 install on your spare drive (with all other drives removed) and see if the card works with a fresh install using Microsoft's provided drivers.
  4. omvs macrumors 6502

    May 15, 2011
    My cMP will bluescreen trying to boot Win7 with both a GT120 and a GTX 680 or GTX 970 - my guess is because the drivers don't support both. I've tried messing with safe mode to disable the GT120, but it just ends up causing both cards to go into legacy/unaccelerated behavior. Ended up getting my GTX 970 flashed by MVC so I could have boot screens (for filevault) and not hose windows with the extra card

    I suspect you might be having a similar issue with Win8 - try pulling the GT120. Or I suspect you could swap in a ATI based card, though you'd need something pretty ancient to have bootscreen and not use a PCIE power connector (HD2600?).
  5. Troy2000, Jun 26, 2015
    Last edited: Jun 26, 2015

    Troy2000 macrumors regular


    Oct 21, 2009
    Is this an EFI Windows installation? Given that Windows 8 can only boot from a Velocity using EFI, I would assume so. That being the case, your GTX 970 would need to be flashed in order to be usable under Windows.

    The alternative is to reinstall Windows using Bootcamp (BIOS emulation) and move your Windows SSD to an onboard SATA port.

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