How to get GTX 1070 to use PCIe 2.0 in Mac Pro

Discussion in 'Mac Pro' started by matthewpomar, Oct 3, 2018.

  1. matthewpomar macrumors member

    Oct 27, 2010
    According to, one must use a modified ROM on a stock PC video card to get it to use the PCIe 2.0 spec vs the PCIe 1.0 spec when installed on a Mac Pro.

    This MacRumors post suggests that it is not necessary to use a "flashed" ROM on an NVIDIA 1070 card if using the web drivers as it will work in PCIe 2.0 mode without being flashed, but Windows will only work in PCIe 1.0.

    However, after purchasing a GTX 1070 Founder Edition and installing the Web Drivers, I'm see the the GPU only has a 2.5 GT/s link speed.

    Does anyone know how to get the GPU to use PCIe 2.0 mode instead of PCIe 1.0? Is the only option to pay for a GPU flashing service?
  2. tsialex macrumors 601


    Jun 13, 2016
    What's your Mac Pro BootROM? You need to enable 5GT/s.
  3. Pressure macrumors 68040


    May 30, 2006
    Run CL!ing to verify whether it runs at PCIe 1.0 or 2.0
  4. h9826790 macrumors G5


    Apr 3, 2014
    Hong Kong
    The link speed is dynamically adjusted for power saving. You may have to run CL!ng or CUDA-Z etc to confirm the actual link speed (depends on cMP firmware).

    That 2.5GT/s in system info is not necessary your card's max link speed. It's been like that for many years.
  5. thornslack macrumors 6502

    Nov 16, 2013
    It was always my understanding that the web driver enabled pcie 2.0 in OS X. I'm still on 10.12.6 running boot rom MP51.007F.B03. I guess I need to do some testing. And update my rom blah :p
  6. flowrider macrumors 603


    Nov 23, 2012
    That's the correct answer. Cuda-Z would can also be used for verification.

    The BootROM or FW makes no difference with Nvidia cards. My cards have always shown 2.5GT/s in the PCI section, but the software mentioned proves otherwise.


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5 October 3, 2018