6850 - second DVI port is dead

[aberberich]

Having an interesting problem since updgrading to mavericks. Previously I was just running 2 monitors on dual DVI. I recently added a 3rd back into the mix (which i had done successfully on mountain lion with no problems). The 3rd screen is connected via active DP -> DVI. It works flawlessly under windows 7 but i have an issue under Mavericks. When I first boot the 3rd screen is very distorted and fuzzy. Once i login I just have to turn the resolution of the 3rd monitor down and than back up and the distortion completely disappears. Any idea how i could fix this?

 

[FishCow]

Having an interesting problem since updgrading to mavericks. Previously I was just running 2 monitors on dual DVI. I recently added a 3rd back into the mix (which i had done successfully on mountain lion with no problems). The 3rd screen is connected via active DP -> DVI. It works flawlessly under windows 7 but i have an issue under Mavericks. When I first boot the 3rd screen is very distorted and fuzzy. Once i login I just have to turn the resolution of the 3rd monitor down and than back up and the distortion completely disappears. Any idea how i could fix this?

Hmm, I'm not sure since I'm not seeing that here.
Only thing I can think of is maybe there's an issue with USB.
Could you try booting with fuzzy screen, then unplugging USB on the active adapter and plugging back in and see what happens?

 

[aberberich]

Hmm, I'm not sure since I'm not seeing that here.
Only thing I can think of is maybe there's an issue with USB.
Could you try booting with fuzzy screen, then unplugging USB on the active adapter and plugging back in and see what happens?

Didn't even consider the fact that the adapter had gone bad since it worked a year ago. Swapped it out for an active DP -> VGA adapter. Works perfect, so it seems like my old adapter had just gone bad. Thanks for the quick response!

 

[Snipeye]

Is there any chance of driving 3 monitors out of the card without an active DP adapter? I have a non-active DP adapter, and I'm trying to drive DVI through that, driving another monitor DVI, and driving a third DVI->VGA. The one in the second DVI port (6850) is currently not showing up (changes around during boot). Is there a chance? Or am I outta luck and have to buy a powered DP adapter?

Additionally, if I bought a powered adapter - looking at startech displayport to vga, active, $20 - would it for sure work?

 

[FishCow]

Is there any chance of driving 3 monitors out of the card without an active DP adapter? I have a non-active DP adapter, and I'm trying to drive DVI through that, driving another monitor DVI, and driving a third DVI->VGA. The one in the second DVI port (6850) is currently not showing up (changes around during boot). Is there a chance? Or am I outta luck and have to buy a powered DP adapter?

Additionally, if I bought a powered adapter - looking at startech displayport to vga, active, $20 - would it for sure work?

I'm afraid your only option is to use DVI 1 DVI 2 and active adapter on one of the DP ports.
or DVI 1 HDMI (disables DVI 2) and Active DP adapter.
At least, that's what I found anyway.
Regards
Fish
P.S I'm no longer using 68xxx card in favour of R9 280x

 

[Snipeye]

Ordered an active adapter, should be here monday. Thanks!

 

[Snipeye]

Slight necro, but update for those interested: The starmax VGA active converter ($20) is working great with the sapphire radeon 6850 under mavericks, I didn't do any weird configs.

 

[aberberich]

For those 6850 user who still show up here for patched ktexts and stuff i wanted to let everyone know that the 10.9.1 update doesn't mess with the video drivers. You should be able to update to 10.9.1 with no effect to your current 10.9 ktext!

 

[Chadster1976]

Hello All,

I am coming to this as a newbie and working on a machine that someone else configured for me to work, but I have a few questions that seemed best possibly answered in this forum. I have read through several posts and this one seems somewhat relevant to my problem.

I have a dual ATI 6870HD setup running 10.8.4. I have 5 total displays running - three on one card and two on another.

Is there a way to mandate which monitor output my desktop defaults to? As of now, the desktop will only show up on the correct monitor if all of the monitors and projectors are on.

If not all of the projectors are powered on, believe it or not, the desktop will actually attempt to be displayed on one of the projectors that are not powered on, rather than the monitor that IS powered on.

The desktop monitor is always the same, so there is no need to switch the desktop from one to another. I am wondering if there is a setting that I am missing in the config files somewhere or if my cards aren't quite configured correctly.

As an aside, I also have to unplug and plug in my monitor that displays the desktop at every startup to sync the signal correctly (it is scrambled garbage otherwise), so something seems slightly off.

I am thinking of attempting this config file mod mentioned in the posts to see if it corrects the problems, but figured I would ask first to see if someone else has encountered this problem before.

Thanks for any help!

 

[insideru]

As fishcow is officially retired from his 6850 career I decided to take over and post the 10.9.2 AMD6000Controller patched according to his teachings

Enjoy