Single card boots, dual cards freeze?

[HumidFume]

Hey guys! Just got my Yosemite up and running perfectly, however one last issue I face. I'm dual booting windows for gaming etc and want to leave my cards sat in the computer. When I have the second card sat in Mac freezes at the Apple screen with the PCI Configuration error.

If I pull it out, bingo loads perfectly.

I have the latest security update (03) and latest drivers (14C1514) but nothing seems to make it load when both cards are sat in the machine. I've looked online for a solution for hours and can't find anything to help.

I've tried PCIRootUID=1, ncpi=0x2000 and 3000, just can't get it to boot. It won't even boot with NVDisable etc..

I thought multiGPU was supported as standard from what i was reading? Perhaps I missed something in the Multibeast? (I installed noDSDT with no other flags / check boxes).

Z87X-UD3H
i5 4670K
GTX 970 x2

Any help would be greatly appreciated!

-Joe

 

[brado32]

Did you get this to work?

I cant get dual monitors to work from startup or restart..

I have tried several smbios settings with no luck..

-B

 

[HumidFume]

Not yet, I'm thinking that changing the system definition to 6,1 might fix it? SLI wasn't around in Macs at 2008 right? Perhaps a newer system definition would work?

Do you need to delete the kexts for 6,1 like you do for 4 and 5?

 

[HumidFume]

Update: I've successfully updated to iMac 14,2 with no problems (updated my SN by randomly generating and saving one using Chameleon Wizard).

The dual GPU setup still won't boot.... What on earth is causing this issue? Anyone?

 

[brado32]

I have spent hours on the forums trying looking for a fix as well. My symptoms are a little different as I am using the internal Intel GFX (4600). I can actually boot with two monitors, but one is totally garbled and distorted.

I am on iMac14,2 as well and doenst work. Only workaround for me is booting with one monitor then plugging in the 2nd one after the system is up and running. Becoming a pain as this machine is not close to the work space..

anyway, good luck. Hope you find a fix

-B

 

[HumidFume]

Thank you mate, best of luck to you also!

 

[HumidFume]

Any help anyone? I'm just gonna sell my second card if I can't get it working. No point having to take it in and out just to swap operating systems