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SOLVED - GTX 6XX hanging on startup with more than 2 displays, please help!

A

All Taken

macrumors 6502a
Original poster
Dec 28, 2009
780
1
UK
I've got my GTX 680 working with my two monitors over vga and dvi, when I plug in my TV via HDMI it's fine if the machine is booted and running but if I restart/shutdown the next time it starts it completely hangs in a grey screen. It won't boot properly until I remove the HDMI screen. How on earth do I fix this? Thanks
 
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jaxhunter

jaxhunter

macrumors regular
Dec 14, 2012
118
15
Maryland Eastern Shore
Are you looking for an explanation or a solution?

I have no solution as one does not likely exist.

As for an explanation the GTX 680 is not officially supported for the Mac Pro. The card you have does not have Mac-compatible firmware and so will exhibit strange behavior upon boot as the Mac's firmware attempts to activate and enable all the video card's features. When it encounters features of the card it can't handle it will halt the boot process to prevent damage to the machine. A different set of drivers are used after boot which is likely why you can use the HDMI port after boot but not during.

In short you will have to tolerate strange behavior if you want to continue using that card with your Mac Pro.
 
A

All Taken

macrumors 6502a
Original poster
Dec 28, 2009
780
1
UK
jaxhunter said:
Are you looking for an explanation or a solution?

I have no solution as one does not likely exist.

As for an explanation the GTX 680 is not officially supported for the Mac Pro. The card you have does not have Mac-compatible firmware and so will exhibit strange behavior upon boot as the Mac's firmware attempts to activate and enable all the video card's features. When it encounters features of the card it can't handle it will halt the boot process to prevent damage to the machine. A different set of drivers are used after boot which is likely why you can use the HDMI port after boot but not during.

In short you will have to tolerate strange behavior if you want to continue using that card with your Mac Pro.
Click to expand...

But do you actually have any idea what is causing this? Do you run a GTX 6XX series card?
 
El Awesome

El Awesome

macrumors 6502
Jul 21, 2012
471
0
Zurich
All Taken said:
But do you actually have any idea what is causing this? Do you run a GTX 6XX series card?
Click to expand...

Did you install the Nvidia driver or are u running the native one?
Try to (un)install it and check if it gets better.
Or try to boot in safe mode (hold shift while booting)
 
A

All Taken

macrumors 6502a
Original poster
Dec 28, 2009
780
1
UK
El Awesome said:
Did you install the Nvidia driver or are u running the native one?
Try to (un)install it and check if it gets better.
Or try to boot in safe mode (hold shift while booting)
Click to expand...

Still no joy, I'm running the latest Nvidia driver. Do you have any issues with your PCI fan ramping up?
 
El Awesome

El Awesome

macrumors 6502
Jul 21, 2012
471
0
Zurich
All Taken said:
Still no joy, I'm running the latest Nvidia driver. Do you have any issues with your PCI fan ramping up?
Click to expand...

A bit yes, something of 1200rpm, but not more.
Try to uninstall the driver and run the native one. They still support Kepler cards.
 
A

Asgorath

macrumors 68000
Mar 30, 2012
1,573
479
Are you using that third-party HDMI audio driver? Perhaps try removing that to see if it's the root cause? I'm only using a single monitor with my GTX 680 and haven't seen any issues like this at all.
 
A

All Taken

macrumors 6502a
Original poster
Dec 28, 2009
780
1
UK
Asgorath said:
Are you using that third-party HDMI audio driver? Perhaps try removing that to see if it's the root cause? I'm only using a single monitor with my GTX 680 and haven't seen any issues like this at all.
Click to expand...

I am and I'm not. I tried it with both but no difference. I can plug in my third monitor when the system is booted and idle but booting with the third plugged in is a no go. This issue is plastered on the hackintosh side but not so much on the Mac Pro side as it's not a native card and few people are using a genuine mac pro with a gtx 680 let alone that and triple monitors. Is this a driver issue or a simple fix that i'm missing? :confused:
 
A

Asgorath

macrumors 68000
Mar 30, 2012
1,573
479
All Taken said:
I am and I'm not. I tried it with both but no difference. I can plug in my third monitor when the system is booted and idle but booting with the third plugged in is a no go. This issue is plastered on the hackintosh side but not so much on the Mac Pro side as it's not a native card and few people are using a genuine mac pro with a gtx 680 let alone that and triple monitors. Is this a driver issue or a simple fix that i'm missing? :confused:
Click to expand...

Huh, I thought I'd seen confirmation that it was working fine. I'll try and dig up an extra couple of monitors and test it myself this weekend, I'm only using a single display with my GTX 680 and it's been rock solid for me so far.
 
jaxhunter

jaxhunter

macrumors regular
Dec 14, 2012
118
15
Maryland Eastern Shore
What's causing it is that the GTX 680 does not have Mac firmware. It is not a Mac video card. It works once the system is booted because the nVidia OS drivers are present but without the appropriate firmware it will not work correctly upon boot.
 
A

All Taken

macrumors 6502a
Original poster
Dec 28, 2009
780
1
UK
jaxhunter said:
What's causing it is that the GTX 680 does not have Mac firmware. It is not a Mac video card. It works once the system is booted because the nVidia OS drivers are present but without the appropriate firmware it will not work correctly upon boot.
Click to expand...

So only cards with EFI can run more than 2 monitors in a Mac Pro?

----------
Asgorath said:
Huh, I thought I'd seen confirmation that it was working fine. I'll try and dig up an extra couple of monitors and test it myself this weekend, I'm only using a single display with my GTX 680 and it's been rock solid for me so far.
Click to expand...

Much appreciated, my 680 is solid otherwise but only having access to 2 outputs blows.
 
A

Asgorath

macrumors 68000
Mar 30, 2012
1,573
479
jaxhunter said:
What's causing it is that the GTX 680 does not have Mac firmware. It is not a Mac video card. It works once the system is booted because the nVidia OS drivers are present but without the appropriate firmware it will not work correctly upon boot.
Click to expand...

What do you mean by "it" when you say it won't work correctly? AFAIK there have been people who got 3+ monitors working just fine with a Kepler GPU running Mountain Lion and the latest NVIDIA driver (note that the NVIDIA driver is currently required as I understand it, the stock Apple driver does not support 3+ monitors).
 
A

All Taken

macrumors 6502a
Original poster
Dec 28, 2009
780
1
UK
SOLVED

Turns out since I was running one DVI and one HDMI the second DVI slot couldn't be DVI-VGA. I purchased a straight through DVI dual link cable and presto 3 monitors. Windows was fine with the DVI to VGA on one DVI port and one DVI to HDMI on the second DVI but OS X was not, it's a driver issue in OS X that hopefully 10.8.3 has fixed.

To anyone reading this and wondering if it is fixable, good news it is as simple as ensuring the two monitors on the DVI ports are DVI-D cables, you can use DVI-D to HDMI or whatever you like but it has to be DVI-D.

The mistake I made was running one DVI port at DVI-D and one at DVI-I.

Two DVI-D is required if using both the DVI ports in OS X, at least with the latest drivers available in OS X and from Nvidia.

Really simple mistake to make and hopefully this helps someone. Thank you for everyones input.

sldldvi.jpg
 
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jaxhunter

jaxhunter

macrumors regular
Dec 14, 2012
118
15
Maryland Eastern Shore
I'm glad you got it resolved! Just be mindful that you may still encounter issues. That being said, I find it encouraging that your Mac pro works with that card. If I may ask, which Mac Pro are you running?
 
A

All Taken

macrumors 6502a
Original poster
Dec 28, 2009
780
1
UK
jaxhunter said:
I'm glad you got it resolved! Just be mindful that you may still encounter issues. That being said, I find it encouraging that your Mac pro works with that card. If I may ask, which Mac Pro are you running?
Click to expand...

It's a 5,1 2012.
 
jaxhunter

jaxhunter

macrumors regular
Dec 14, 2012
118
15
Maryland Eastern Shore
All Taken said:
So only cards with EFI can run more than 2 monitors in a Mac Pro?

EDIT; I haven't figured out the quote thing... The above question was posed by All Taken.

Sort of yes, sort of no. Graphics cards with the correct Mac firmware will work in all situations. Cards without the correct Mac firmware will exhibit strange behavior, especially during POST and during Boot. During that time the only video drivers available to the system are what's contained in the Mac's firmware and the graphics card's firmware. If something is missing from the Mac's firmware it looks to the graphics card's firmware to fill in the holes. If it still cannot resolve any issues it will halt the boot process. After OS loads the firmware dioesn't really matter anymore (for all practical purposes) and more sophisticated drivers take over and enable all the functions of the card.

So in this case it may be that you were using the wrong connection or that because of the missing firmware the Mac was unable to force the graphics card to perform a switching function of some kind to enable the use of the HDMI port in conjunction with the particular DVI cable you were using. By switching cables you may have manually made the necessary switch or bypassed whatever conflict existed. It also may just be a limitation of the card itself. it could have nothing to do with the Mac at all.
Click to expand...
 
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