Flashed GTX 980 and 7850 causing lockup at boot in Mac Pro 4,1?

[Troy2000]

Greetings.

So, I have a Mac Pro 4,1 (5,1 firmware) with an NVIDIA GTX 980 and AMD 7850 installed, both of which are flashed.

The problem is that whenever I attempt to boot without a monitor connected to 7850, the Mac Pro always freezes upon reaching the gray boot screen (prior to booting the OS) and the fans begin to ramp up. I can successfully boot into OS X by connecting a monitor to both GPUs but all attempts to boot Windows end in a black screen followed by a reboot.

My intention was to use the 7850 for Mountain Lion and the 980 for Windows 10 but as far as I can determine, there is some kind of EFI conflict taking place. I have found that if I reflash the 7850 with its original PC ROM, the freezing on boot disappears. This would be a perfect solution but it also means that when booting Mountain Lion, the 7850 only initializes if there is a monitor connected to the 980.

My only real recourse at this point is to purchase an active DisplayPort adaptor for the 980 to simulate a permanently connected display, so I would be very grateful for any input.

Thanks!

 

[netkas]

Try to connect monitor to only 7850 on bootup.

 

[Troy2000]

Try to connect monitor to only 7850 on bootup.

If I do that while the 7850 is running the EFI ROM, the Mac Pro freezes on boot. If I try it with the PC ROM, everything behaves normally except for the fact that the 7850 doesn't initialize under OS X without also having a monitor connected to the 980.

 

[MacVidCards]

If you got the card from us, I might have a fix.

 

[Troy2000]

If you got the card from us, I might have a fix.

No, I purchased it elsewhere. I had wanted to purchase it from you but it was not listed on the MVC site.

 

[MacVidCards]

Then you have a hijacked rom that has errors in it. Those clowns in NC couldn't hack their way out of a wet paper sack. Ask them to fix it.

 

[Troy2000]

Then you have a hijacked rom that has errors in it. Those clowns in NC couldn't hack their way out of a wet paper sack. Ask them to fix it.

The seller has told me that the ROM was created using the 7xxx tool from Netkas. I could generate one myself and see if it solves the problem.

 

[MacVidCards]

The 980 is the one I meant.

 

[Troy2000]

The 980 is the one I meant.

Ah, I see. Yes, the 980 was sent to you for flashing.

 

[MacVidCards]

please email me for a test I can have you run

 

[Troy2000]

please email me for a test I can have you run

I have emailed you at the address listed on the MVC contact page.