When I turn on my PC it will show Clover on the 1080p monitor and the other two DP monitors will go into standby, if I boot OSX like this then all monitors will black screen instead of showing the login screen. The DP monitors will go into an endless loop of trying to get a signal and saying "Display Port" like they do when looking for a singal and the 1080p DVI one will just display a black screen. The system is not hung, I can still ssh into it.
The only way for me to successfully boot and have all 3 monitors work is either to:
- fully turn off both DP monitors, boot only with DVI until log in screen, then turn on both DP monitors
- manually turn on both DP monitors while booting but before it comes to the login screen, so they are not in standby
But if I just let it start normally it without doing either it black screens.
The same thing also happens when I'm already logged in and have it running successfully and turn off all monitors and come back later. Usually (8 out of 10 times) when I turn them all on it works again, but the other 2 times all of them start to black screen the same way. It seems the most consistent way to avoid that is to turn both DP monitors on at the same time.
What I've tried so far:
- SMBIOS 14.2, 15.1, and MacPro 6.1 (the current one), none of that helped.
- Lilu.kext + NvidiaGraphicsFixup
- Patching AppleGraphicsDevicePolicy.kext/Contents/Info.plist and setting everything to none
- Switching the 1080p monitor to HDMI but that was the same, can't switch the DP monitors really since they are 4k and need DP.
Nothing had any effect.
i7 4790k, GA-Z97X-UD3H, 32gb
980Ti (reference card) driver 3188.8.131.52.25.104 (should be the latest one)
2x Samsung 4k monitor (Display Port)
1x 1080p via DVI