GTX970 Boots with Single monitor but not with Dual

[clamk]

I just finished a Clover install with Yosemite 10.10.2 that works just fine with a single monitor in Dual link DVI. If I have second monitor connected, the computer is unable to boot. It is able to go past the apple loading screen but the machine resets right when it gets to the user login page. Tried booting in -v to see if I could find an error but it doesn't show up because it is able to get to the login page.

Strangely enough if I plug in the second monitor AFTER the system is booted up and logged in, they both monitors work just fine.

I searched and was unable to find anything about this type of issue, especially with Nvidia cards. My card is a GTX 970 but that seems to be supported just fine in Yosemite. I do have the web drivers installed and nvda_drv=1. I did not inject Nvidia drivers though as that doesn't affect the issue. Intel Drivers are injected. Not sure what the problem is or how to go about approaching it. I did see something about frame buffers but that didn't seem to be a Nvidia issue at all.

During the clover install a patched SSDT was used to enable speedstep but I didn't use a custom DSDT.

A list of parts for my build below are listed if that helps. My motherboard is relatively old but I'm not sure if that's the issue:
CPU: i5-2500K
MB: Gigabyte Z68MA-D2H-B3 U1c (UEFI)
RAM: 8GB DDR3
GPU: MSI GTX970

Thanks for any help!

 

[dobo2001]

What are you using to connect the second monitor? DVI is the most supported, while HDMI and VGA are kinda sketchy.

 

[clamk]

I tried using DVI and Displayport. Didn't do HDMI because of the support issues I read about and there isn't VGA on that card.

 

[dobo2001]

Which boot flags are you using? Have you tried GraphicsEnabler=No/Yes?

 

[clamk]

It's clover so that bootflag isn't there. I used what I think is the equivalent where you Inject Intel GFX but not Nvidia.

The bootflags I did use are dart=0, kext-dev-mode=1, and nvda_drv=1 (Used after I installed drivers for GTX970)

 

[kundica]

What SMBIOS are you using? I have the same issue using MacPro6,1 but it will work find with MacPro5,1. The problem with MacPro5,1 for me though is my CPU PM doesn't work.