Mac Pro GTX680 Windows EFI problem

[Squuiid]

I'm having problems getting my GTX 680 Mac Edition card to work in EFI mode in Windows 8.1/10.
I have to install Windows in EFI mode in order to use a PCIe XP941 SSD, and have it boot from it.
(Installing Windows in BIOS mode using a Windows CD to a SATA SSD in bay 1 works fine.)

Every time I install Windows 10 in EFI mode it works fine using the Standard Display Adapter driver but as soon as I install the NVIDIA drivers, BAM, black screen/lockup. I have to hold down power to shutdown.

I then need to reinstall Windows and try again!

Any ideas why I'm getting this black screen/lockup as soon as I install the NVIDIA driver? Is the 680ME not compatible in a UEFI Windows installation?

 

[ActionableMango]

I think it works fine, but I'm not sure. I switched to Windows EFI last year and I've had both 680 and 980. But I'm not 100% sure I switched to EFI before I switched to the 980. Hopefully someone else can chip in who is certain.

I can say for sure that 980 with Mac EFI works on Windows 10 EFI with Nvidia drivers, as that is what I'm using right now.

 

[Squuiid]

I think it works fine, but I'm not sure. I switched to Windows EFI last year and I've had both 680 and 980. But I'm not 100% sure I switched to EFI before I switched to the 980. Hopefully someone else can chip in who is certain.

I can say for sure that 980 with Mac EFI works on Windows 10 EFI with Nvidia drivers, as that is what I'm using right now.

Thanks ActionableMango. If someone else has experience and can confirm either way I'd be really grateful. This is driving me nuts. I've lost count of how many times I've installed Windows now. Please save me!

 

[netkas]

980 with mac efi is much more friendly to windows on efi, unlike 680.

 

[Squuiid]

980 with mac efi is much more friendly to windows on efi, unlike 680.

Thanks netkas. I think I'm going to wait until NVIDIA release Pascal in June and see how that pans out on the Mac.
[doublepost=1457015191][/doublepost]What I ended up having to do is ditch one of the XP941 blades and install an SSD in SATA bay 3 instead.
(Do not use bay 1 as the ATA controller on bay 1, in Windows, is shared with the Superdrive and this hits disk performance significantly.)

Then install Windows 10 using a CD, in BIOS mode, to the SATA SSD. (Windows on a USB flash drive will only install EFI mode on a Mac Pro 5,1. We need BIOS mode, not EFI, for the GTX 680 to work)

Once installed, Windows 10 automatically installs the latest NVIDIA drivers from the web. I then installed the 6.0.6237 BootCamp drivers and done!

The downsides to this are a) I can't use my second XP941 as a Windows drive and b) the SATA SSD runs in IDE mode not AHCI. The Samsung 850 Pro maxes out at 228MB/s read and 221MB/s write. Good enough for me.

On the plus side, I can now game in Windows with a decent gfx card on my Mac Pro 5,1