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Windows 8.1 Native EFI Not Detecting GTX 980? (cMP 4,1)

Troy2000

Troy2000

macrumors regular
Original poster
Oct 21, 2009
201
77
Greetings, all.

I come to you with something of a perplexing issue today. Last month, I purchased an 8-core 2009 Mac Pro and proceeded to shower it with every upgrade under the sun.

Its current specifications are as follows:

CPU: Intel Xeon X5690 (2 CPUs/3.46GHz/12 physical cores)
RAM: 48GB DDR3-1333
GPU: NVIDIA GTX 980
SSD: 1TB+128GB Samsung 840 EVO
HDD: 5TB Seagate (x4)
Misc: Apricorn Velocity Solo X2, Sonnet Allegro USB 3.0, Blackmagic Intensity Pro

My ideal vision for this workstation was to run Windows 8.1 from the 1TB SSD connected to the Velocity Solo X2 and run OS X 10.10 from the 128GB SSD connected to the extra SATA cable in the second optical bay.

This sounds simple enough in theory but as it turns out, Windows 8.1 is not capable of booting from the Velocity Solo X2 under BIOS emulation mode. As a result, I was forced to install Windows 8.1 in native UEFI mode, which was where the problems became apparent.

The biggest problem was that while Windows 8.1 had no complaints in booting from the Solo X2 under UEFI mode and overall boot times did improve, I quickly discovered that there was no video output whatsoever from my GTX 980. I tried swapping my Apple 4870 back in, hoping that installing the GTX 980 driver first might help but NVIDIA's installer refused to run without a suitable GPU present.

The only "solution" to this problem which I have been able to implement was to connect the 1TB SSD to an internal SATA port and install Windows under BIOS emulation mode. That did allow me to use the GTX 980 but it also meant that my 1TB SSD was limited to SATA II speeds and the GTX 980 to PCI-E 1.1 speeds. As you might imagine, this is far from ideal.

Another potential solution that I have been considering is to boot Windows from the Solo X2 in UEFI mode with both the 4870 (powered externally) and GTX 980 connected so that I can reach the desktop and install drivers for the latter without NVIDIA's installer complaining. Whether this would actually work is anybody's guess but I'm rather tempted to try it.

Anywho, my apologies for this unwieldy wall of text. If anybody could offer some advice, I would be eternally grateful. :p

Thank you!

Troy
 
I thought that I'm the only one trying to run Windows 8.1 in EFI mode... I happen to have a lot of Mac Pros and various graphic cards. the only card I got to work reliable under Win 8.1 was the Radeon HD 5770. not even the Apple GeForce GT 120 worked. again, this only applies to Win 8.1 and only if installed in EFI mode.
 
mikeboss said:
I thought that I'm the only one trying to run Windows 8.1 in EFI mode... I happen to have a lot of Mac Pros and various graphic cards. the only card I got to work reliable under Win 8.1 was the Radeon HD 5770. not even the Apple GeForce GT 120 worked. again, this only applies to Win 8.1 and only if installed in EFI mode.
Click to expand...

Was the 5770 an Apple EFI card or a non-flashed PC card?

I would really love to hear from MacVidCards on this issue.
 
it's an OEM Apple 5770, not a flashed generic one.

Radeon HD 7970 (flashed EFI), GeForce GTX 680 (flashed EFI), GT 120 (Apple OEM): all no-go.
 
Very interesting topic.

I'm guessing that the 980 is PC version?

This is where it all gets sticky. PC UEFI is different from Mac EFI. And there are several versions of Mac EFI.

But I have been fighting this battle on another front. Working on eGPUs there is a big difference in MBR versus EFI installs of Win 8. I just checked and my 4,1/5,1 is MBR.

Tell me this, what is quickest way to have a EFI install, do I have to redo the whole deal?

Or can I format a disk in GPT and use WinClone? I think I will try that as I am not eager to do a fresh WInstall followed by exactly 1 million updates.

Also, I'm pretty sure an unflashed 980 is going to be at PCIE 1.0 speed no matter how Windows is installed. The Nvidia drivers fix it for OS X on 4,1/5,1 but have no magic powers in Windows.
 
MacVidCards said:
Also, I'm pretty sure an unflashed 980 is going to be at PCIE 1.0 speed no matter how Windows is installed. The Nvidia drivers fix it for OS X on 4,1/5,1 but have no magic powers in Windows.
Click to expand...

Good read. I just purchased a EVGA GTX980 SC ACX version that I put into my 5,1 Mac Pro.

So with the current Nvidia drivers, does it operate at PCIE 2.0 speeds?

Is the PCIE 1.0 speeds limited to just Windows use at this point?
 
MacVidCards said:
Very interesting topic.

I'm guessing that the 980 is PC version?

This is where it all gets sticky. PC UEFI is different from Mac EFI. And there are several versions of Mac EFI.

But I have been fighting this battle on another front. Working on eGPUs there is a big difference in MBR versus EFI installs of Win 8. I just checked and my 4,1/5,1 is MBR.

Tell me this, what is quickest way to have a EFI install, do I have to redo the whole deal?

Or can I format a disk in GPT and use WinClone? I think I will try that as I am not eager to do a fresh WInstall followed by exactly 1 million updates.

Also, I'm pretty sure an unflashed 980 is going to be at PCIE 1.0 speed no matter how Windows is installed. The Nvidia drivers fix it for OS X on 4,1/5,1 but have no magic powers in Windows.
Click to expand...

Yes, my GTX 980 is the standard PC version (EVGA reference, specifically).

Unfortunately there is no way to "convert" an MBR installation to EFI; you would need to boot a Windows 8.1 installation DVD and then use the CLI to both format your HDD to real GPT and create the appropriate system partitions. The Windows EFI installer is extremely picky about not supporting hybrid GPT disks created by OS X.

PowerMike G5: Your GTX 980 will only be limited to PCI-E 1.0/1.1 under Windows. It amounts to a real world difference of 6-10 FPS in most GPU intensive games.
 
Troy2000 said:
Yes, my GTX 980 is the standard PC version (EVGA reference, specifically).

PowerMike G5: Your GTX 980 will only be limited to PCI-E 1.0/1.1 under Windows. It amounts to a real world difference of 6-10 FPS in most GPU intensive games.
Click to expand...

Thanks! I assume under use in OS X Yosemite that it is running at PCIE 2.0? Is that mainly due to Nvidia's latest webdrivers?
 
I seem to recall trying to use the EFI install option when I put 8.1 on this Mac Pro and it just locked up the installer.

I know there needs to be a 200MB EFI partition in Fat32 that has Apple and Microsoft folders on it.

I don't partition disks for Windows, i just use the whole disk, nice thing about having 6 Disk slots and extra PCIE slots. Options and variety, the very things lacking on nMP.

I have read of people converting these disks using diskpart utility in Windows. I would rather just create a GPT disk and move the files onto it, I have 2 EFI installs on my nMP and 2014 Mini so could mimic the partitions and contents from there.
 
MacVidCards said:
I seem to recall trying to use the EFI install option when I put 8.1 on this Mac Pro and it just locked up the installer.

I know there needs to be a 200MB EFI partition in Fat32 that has Apple and Microsoft folders on it.

I don't partition disks for Windows, i just use the whole disk, nice thing about having 6 Disk slots and extra PCIE slots. Options and variety, the very things lacking on nMP.

I have read of people converting these disks using diskpart utility in Windows. I would rather just create a GPT disk and move the files onto it, I have 2 EFI installs on my nMP and 2014 Mini so could mimic the partitions and contents from there.
Click to expand...

Ignoring the segments pertaining to dual booting, I used this as a reference for my EFI installation.
 
Troy2000 said:
Ignoring the segments pertaining to dual booting, I used this as a reference for my EFI installation.
Click to expand...

wow, this looks rather complicated. I just option-booted from the windows DVD, chose the EFI installer and installed it onto a separate drive. to make sure that nothing happens to my other operating systems (various OS X versions and Linux) I just pull the other drives during installation.
 
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In bootcamp mode, the card is initialized by it's own videobios

in uefi mode, what you expect would initialize the card?

it comes uninitialized to windows and that might cause you the issues.

send it to MVC for flashing, would resolve issue.
 
netkas said:
In bootcamp mode, the card is initialized by it's own videobios

in uefi mode, what you expect would initialize the card?

it comes uninitialized to windows and that might cause you the issues.

send it to MVC for flashing, would resolve issue.
Click to expand...

I'm actually quite tempted to do that but as far as I know, MacVidCards won't offer his flashing service to customers outside of the US (I am in Ireland).
 
mikeboss said:
I highly doubt that this would solve anything. the NVIDIA drivers were crashing hard the last time I tried to run this. the only card I got to work was an Apple OEM Radeon 5770.
Click to expand...

It is actually quite possible that EFI on the card could fix this. I will try to do an EFI install on 4,1 if I can't do it easily I will just place a drive in my 2014 Mini and use that. Little understood fact is that Bootcamp's default behavior switched to EFI installs on newer machines.

If you go to DIY eGPU boards at Tech Inferno you will see that there are several systems that NOBODY could get working. At least until MVC came along and started creating eEFI roms for the eGPU.

The eEFI is different from EFI on cMP. (Thanks Apple !) my 2012 rMBP couldn't use eGPU in Windows and would always get an Error 12. This meant that by the time Windows liaded no address space had been mapped for the GPU and thus it was useless. There is a complicated series of workarounds involving the creation of a custom DSDT that maps the memory at boot.

I put an eEFI on GTX780 and booted right into Windows with no error 12. The eEFI hands the card off to the OS.

The only person who has enabled display output in OSX on nMP IS US, via eEFI. Same with 2014 Mini. Same with 2014 rMBP using the Iris card only. Everyone else who has tried on those 3 systems stares at a black screen and can only use CUDA or OoenCl.

So don't underestimate what EFI can do. The pretty boot screens aren't the only reason to use it.

So, when I find time I will give it a shot.
 
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Yes, works fine for me. Like MikeBoss, I just selected EFI Boot from the Windows DVD and installed it. I didn't do any of that other stuff you linked to.
 
since I have recently acquired an Apple OEM 5870 I just tried this card: works!

EDIT:

GTX 760 (from MacVidCards with EFI) also not working. just to be clear: getting a picture doesn't mean everything's running fine. the driver crashes and windows reinstalls the generic display driver. so you'll get a picture but not with the right drivers running.
 
Last edited:
MacVidCards said:
It was VERY simple to do an EFi instal of 8.1 on 4,1

The GPU is much more complicated

Even an Apple 4870 doesn't seem to work well for me
Click to expand...

That's strange, I actually had no trouble at all with my Apple 4870 under Windows with EFI.
 
mikeboss said:
and what type of graphics card are you running in the Mac Pro?

just to be clear: getting a picture doesn't mean everything's running fine. the driver crashes and windows reinstalls the generic display driver. so you'll get a picture but not with the right drivers running.
Click to expand...

EVGA GTX980 SC 4GB ACX 2.0 with MVC EFI. There were no crashes and the Nvidia driver is running. Attachment verifies Nvidia drivers and EFI install. FWIW, I'm using the top Display Port.

I did nothing special, just same as you (selected EFI boot from the Win 8.1 Pro install DVD).

I've noticed some other bootcamp-related problems, like incorrect clock time and my selected boot volume not sticking, but no problems with graphics.
 

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ActionableMango said:
EVGA GTX980 SC 4GB ACX 2.0 with MVC EFI. There were no crashes and the Nvidia driver is running. Attachment verifies Nvidia drivers and EFI install. FWIW, I'm using the top Display Port.

I did nothing special, just same as you (selected EFI boot from the Win 8.1 Pro install DVD).

I've noticed some other bootcamp-related problems, like incorrect clock time and my selected boot volume not sticking, but no problems with graphics.
Click to expand...

nice! does it stay like this even if you restart the system? no nvidia/driver crashes visible in the system logs?
 
ActionableMango said:
EVGA GTX980 SC 4GB ACX 2.0 with MVC EFI. There were no crashes and the Nvidia driver is running. Attachment verifies Nvidia drivers and EFI install. FWIW, I'm using the top Display Port.

I did nothing special, just same as you (selected EFI boot from the Win 8.1 Pro install DVD).

I've noticed some other bootcamp-related problems, like incorrect clock time and my selected boot volume not sticking, but no problems with graphics.
Click to expand...

Nice... I'm thinking of getting one of these or a Titan X for my birthday (present to myself).
 
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