Apple Cinema Display 24" and Radeon HD 6870 with Mini DP not working on Clover :(

[benjaminmlynek]

Do you know if it has something to with the atiports flag in Clover? I think it's set to 4 right now. But the card has 2 DVI, 2 mDP and 1 HDMI. Does that make a difference?

 

[Fl0r!an]

I think this only affects the 2nd DVI port as this is the "last" one which will be left out.
Again, did you try using your card without any injection?

 

[benjaminmlynek]

Yes i have tried without injection, but without any luck This is getting really frustrating, can't seem to get that damn mDP port working when booting

 

[benjaminmlynek]

Okay so now i just found out that when it hits the login screen in Yosemite and i then hit my turn off button on the computer for 1 sec and put it to sleep, and then afterwards press a key to get it to wake again i works :S So it must be something with it not booting in the right resolution or loading recognizing the gfx card on boot? Hmm....

 

[Stork]

I think this only affects the 2nd DVI port as this is the "last" one which will be left out.
Again, did you try using your card without any injection?

I can confirm that two DVI ports will not drive two monitors with my Gigabyte HD6850 card. But, I believe that is stated in the port configuration table in the card's user manual.

 

[benjaminmlynek]

Is the 6870 is working with full acceleration?

Yeah but the problem isn't the graphical performance here. The problem is the mini displayport during boot

 

[rocco_77]

I'm resurrecting this thread because this is the exact issue I have with my set up in El Capitan.

I get a very similar one quadrant flickering login screen.

The work around I used was to set the Init Display First to Onboard instead of PCI. I don't see anything during post or the boot loader, but it gets to the login screen with both monitors. I have 2 20" ACDs. One on a DVI and one with DVI to mDV adapter.

In my Display settings on the OS I have a third smaller screen showing up which I'm sure is the onboard port being activated. I just put that screen all the way to the right in the screen arrangement and all is well.

I would like another solution to this if anyone has any thoughts.

 

[rocco_77]

@Stork

I've searched the forums for an answer to this, but I can't find another solution beyond my work around mentioned in my post above.

Interesting thing is that when booting with the USB, it works fine. Guess I could take a look at the USB clover config file to see if there are any differences to the one on the SSD.

This was happening to me the entire time when I made that thread about not booting without the USB. Thing is, it was booting, just not initializing the graphics card properly without the USB mounted.

Have you come across any others with this issue that solved it other than setting bios to Init Display First : Onboard. ??

 

[Stork]

I have not had a problem driving two displays with my Son of Zorro build which uses a 6850 graphics card (DVI and DP to DVI adapter). You don't need to have the BIOS set up with the iGPU booting first. You must have all your graphics Inject's in the Config.Plist file set to "false".

 

[rocco_77]

I have not had a problem driving two displays with my Son of Zorro build which uses a 6850 graphics card (DVI and DP to DVI adapter). You don't need to have the BIOS set up with the iGPU booting first. You must have all your graphics Inject's in the Config.Plist file set to "false".

Yes I realize that. This thread talks all about injecting, not injecting. The thread author here has gone through the permutations and eating and still ends up with the same result.

The only thing I haven't tried is putting my gfx card personality in the config file.

You gave me instructions in my other thread on creating the boot USB and what multibeast settings to use. e.g. No injection.

The only thing that is happening is when I boot from SSD with Init Display First set to PCI is when I get the issue the thread author had. And no one had any other option. I found the workaround for setting Oboard first on another forum. That's the only thing that has worked.

The question is, what is the difference when booting from the USB, which initialized the display fine, and booting directly from the SSD that does not initialize the gfx card properly?