Hint: 10.6.4 on Mac Pro 5,1 with 980Ti

[monkeybagel]

Long story short - I had to reformat my Mac Pro 5,1, which came with an ATI 5870 GPU, and now has a flashed GTX980Ti installed. Not expecting to get anywhere, I tried to boot from the 10.6.4 DVD and low and behold it worked fine. No acceleration of course, but it was able to install, update to 10.6.8, and update using the Mac App Store to upgrade 10.11.4. Not sure if anyone will run into this issue in the future, but I thought I would post my findings in the event it would help someone at a later date. I know I should have had a USB installer of a later OS but under the circumstances, I only had the Snow Leopard DVD. I am sure this is only because the GPU is flashed, but it did indeed work to my surprise!

The topic is meant to say 980Ti - Mods please correct.

 

[Macdctr]

Don't update to 10.11.5 with this card. There are no Nvidia web drivers that will work with this update and your GTX980Ti will not work right. I had to remove my GTX980 from my rig and put in the original graphics card to restore my OS. For some reason with my GTX980 installed, it kept causing kernel panics whenever trying to restore my OS.

 

[dlindsey100]

I also made the mistake of upgrading to 10.11.5 without first checking to see if there was an updated driver. Luckily for me, my MVC GTX980TI still worked well enough with the default driver that I was able to easily revert back to a previous backup.

 

[Zlobnick]

I have flashed GTX 980 (non-Ti, works fine with boot screens) in my 5,1. If I update my OS from 10.11.3 to 10.11.4 will I see the desktop, at least without acceleration, just so I can update the nVidia driver? Thanks!

 

[Macdctr]

I have flashed GTX 980 (non-Ti, works fine with boot screens) in my 5,1. If I update my OS from 10.11.3 to 10.11.4 will I see the desktop, at least without acceleration, just so I can update the nVidia driver? Thanks!

I'm running 10.11.4 with my GTX980 without any issues... just don't update to 10.11.5 yet....

 

[Zlobnick]

I know it works, I'm just wondering what will happen if I press update to 10.11.4 and restart Will there be a desktop visible, or not until I somehow install new nVidia web drivers? Once again, the card is flashed and shows the boot screens.

 

[monkeybagel]

Don't update to 10.11.5 with this card. There are no Nvidia web drivers that will work with this update and your GTX980Ti will not work right. I had to remove my GTX980 from my rig and put in the original graphics card to restore my OS. For some reason with my GTX980 installed, it kept causing kernel panics whenever trying to restore my OS.

I haven't upgraded to 10.11.5. I try not to run beta software on my production machine. But thank you for the hint.

 

[ActionableMango]

I know it works, I'm just wondering what will happen if I press update to 10.11.4 and restart Will there be a desktop visible, or not until I somehow install new nVidia web drivers? Once again, the card is flashed and shows the boot screens.

You should be able to boot in. It will not be accelerated, and it will be slow. Then you can install the Nvidia drivers from web. This is how it works for me with my flashed 980.

If there's an endless boot loop, follow the instructions on MVC's FAQ for booting into single user mode.