GT640 in Mac Pro 1,1 (Tiamo Mavericks) issue

Discussion in 'Mac Pro' started by TBear12, Aug 1, 2014.

  1. TBear12 macrumors newbie

    Aug 1, 2014
    Hey everybody. I'm new to the forum and I was wondering if I could get some advice regarding a Gigabyte 2GB Graphics Card in a 2006 Mac Pro (2.66 Dual Dual Core Xeon, 4GB Ram)

    After doing some research in regards to a "supported graphics card" for a Mac Pro hacked into Mavericks 10.9.4 using Tiamo's boot.efi, I opted for a Gigabyte GT640. I was informed that the GT640 was plug and play for Mavericks, bar the boot screen, and everything would be alright. However, after installing Mavericks on my Mac Pro, I found that the GT640 would not output any signal to my monitor, which runs off VGA. I installed the old 7300GT in Slot 4 (the GT640 is in slot 1), which is unsupported and runs sluggishly, and it powered the display okay. I checked the System Report and it recognised both the GT640 and the 7300GT. Also, I found that although some apps like Safari and Quicktime demonstrated flickering and graphics tearing because I was powering the display off the 7300GT, other apps such as Firefox and Motion ran perfectly fine. I installed DaVinci Resolve Lite and it recognised the GT640.

    I thought it might have been an issue with the VGA port, so I purchased a VGA to DVI-D adapter, but still I am having no success. I have also tried switching between the NVIDIA drivers and the OS X drivers, which also did not work.

    Not sure if anybody had any ideas or has had the same issue. Thanks for your time!
  2. B34NS macrumors newbie

    Nov 20, 2014
    After running Mavericks's 10.9.1 on my 1.1 with a Sapphire HD 7970, worked for the last few months flawlessly. Just this week I had the same problem, thinking it was the video card I tried some tests, but boots past post only with the 7300GT installed, back to snow leopard. The biggest challenge is trying to get the newer yosemite to install with the tiamo method, for some reason I think the EFI boot process might be different?
  3. Kipsley macrumors member


    Nov 12, 2015
    Western Australia
    I aso have a Nvidea GT 640. It's not flashed or anything. I'm having El Capitan installed on my 2006 Mac pro 1,1 and then I'll see if I can't just "plug in" the GT 640.

    I'm on Lion 10.7.5 and just recently upgraded my graphics to AMD 5770 and found some issues. Using VGA cable with adaptor gave me the boot screen but nothing else. Switching to old style cable gave me the Desktop, but no boot screen (as this 5770 is flashed). So plugged in both cables and now have everything. :)

    Have you tried using the older style cable?
  4. TBear12 thread starter macrumors newbie

    Aug 1, 2014
    Hi! The GT640 was phantom powered so it didn't need any cables. However, I got rid of that card and got a Mac edition 5770. Thanks for replying though :)
  5. d3vCr0w macrumors newbie


    Jan 23, 2016
    I got the same GT 640 card and I'm having the same issue, does anyone know a possible solution?

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