30 Minute Black Screen on Mac Pro 5,1

[sdwaltz]

Following up to this post.

I did successfully install Windows 11 on my 2012 5,1 and it runs really well but with a couple caveats...
1) Wifi is incredibly slow (ethernet is not)
2) The much bigger deal: even with the most recent Windows 11 Nvidia driver downloaded and installed straight from Nvidia (GTX 680), the computer boots to a blank screen for 30 minutes or so and then after that, it shows the logon screen as if nothing was ever wrong. It shows the Windows logo during startup, and then goes blank after that. No cursor, and my monitor tells me it's receiving no signal and goes to sleep. Even more interesting: the front USB ports don't work during this time (I know this because the light on my caps lock key doesn't illuminate when pressed), and after that 30 minute wait, they work again. I feel like this has to be connected somehow?

I downloaded bootcamp drivers using a machine on Catalina, installed them, and it didn't help - actually, it made it worse because I had to wait the same 30 minutes and then couldn't get into the OS at all (got BSOD).

Has anyone managed to successfully put Windows 11 on a 5,1 with a GTX680 without this weird 30 minute wait?

 

[bobcomer]

I feel like this has to be connected somehow?

I would say so.

It sounds like the MP is in a wait state for that half hour. Not booted up at all. Hard to tell if it's the BIOS doing the wait, or the OS. If you have any other USB devices that are plugged in other than the keyboard and mouse, try unplugging them and see if it makes a difference.

I don't have any experience with the Mac Pro, but I am pretty good with Windows...

 

[sdwaltz]

Good news. I did and changed nothing, but this now seems to have worked itself out. I've restarted it 10 times just to make sure and it's been a normal boot every time. I guess we'll consider this one a mystery.