Switched from GTX 970 to GTX 1070 on a MacPro5,1 — no video in Windows 10 (UEFI boot)

[star-affinity]

I can hear that Windows is making sounds and I can shut down the computer gracefully ”in the blid” using the keyboard, so it seems Windows 10 boots just fine, but I get no video on my display. Is Windows perhaps confused and think I still have the GTX 970 GPU in there?

The 1070 works fine when booted into MacOS High Sierra (10.13.6).

I'm thinking about putting back the GTX 970 and uninstall the video card drivers and then shut down the computer, switch to GTX 1070 and see if Windows gets happier.

What would you do?

Thanks in advance for any replies!

 

[h9826790]

I can hear that Windows is making sounds and I can shut down the computer gracefully ”in the blid” using the keyboard, so it seems Windows 10 boots just fine, but I get no video on my display. Is Windows perhaps confused and think I still have the GTX 970 GPU in there?

The 1070 works fine when booted into MacOS High Sierra (10.13.6).

I'm thinking about putting back the GTX 970 and uninstall the video card drivers and then shut down the computer, switch to GTX 1070 and see if Windows gets happier.

What would you do?

Thanks in advance for any replies!

Did you wait for 5-10 min to let Windows install the driver?

(I assume you didn’t block the Win 10 auto driver update)

 

[star-affinity]

Did you wait for 5-10 min to let Windows install the driver?

(I assume you didn’t block the Win 10 auto driver update)

I think I waited that long, yes. But maybe I was too eager…

What I tried next (TL;DR – it worked):

-Put back the GTX 970 and booted into Windows 10 (with video) and there I uninstalled the Nvidia Display Driver and turned off the computer and put the GTX 1070 in and attempted boot into Windows: no video seen.

-Put the GTX 970 in again and attempted boot into Windows: no video seen.

-Put the Radeon 5870 that came with the Mac Pro in and attempted boot into Windows – got stuck at Windows logo and no other info for about 30 minutes. Force shut down the computer.

-Restarted the computer again (still with the Radeon 5870 and golding down alt/option and pressed to select the Windows EFI to boot from it). This time I got video and could log into Windows which after some time installed ATI/AMD drivers automatically.

I then decided to run the Guru3D uninstaller here: https://www.guru3d.com/files-details/display-driver-uninstaller-download.html

-Having the Radeon card in still I first cleaned out all the Nvidia drivers and restarted, then I cleaned out all AMD drivers and shut down and put the GTX 1070 back in the computer and restarted into Windows: no video seen. I waited for at least 20 minutes and the display stayed dark. In managed to log into my Windows account ”in the blind” and waited there for another 15 minutes, then I managed to shut down the computer from within Windows ”in the bild” (alt F4 and some keypress guessing…).

-I'm now back in MacOS using the GTX 1070 and will attempt to restart into Windows… IT WORKS!

Thanks for reading. And thanks to the folks at Guru3D I guess?