ATI dual screen not working in 9.04

Asked by myxiplx

I'm running an ATI Radeon X1950 Pro, it was working fine in 8.10, but since upgrading to 9.04 I can't get dual screen graphics to work at all.

Immediately after the upgrade to 9.04, I couldn't log on. Any attempt to do so just crashed me straight back to the logon screen, similar to the problem reported here:

I managed to log in after removing my entire .config directory, but then found that I could not configure dual screen graphics. Although the graphics card and both monitors appear to be detected fine, any attempt to turn off 'clone' mode immediately crashed Ubuntu back to the logon screen, and prevented that account logging in until I removed the .config directory again.

Next I tried the ATI drivers, going to System -> Administration -> Hardware Drivers to enable them. They installed fine, but after rebooting I had a completely corrupted display, the screen was unreadable and unusable. Even in recovery text mode I was getting graphics corruption and strange characters appearing on the display, but I managed to recover by removing the ATI drivers with the command:
# apt-get remove --purge xorg-driver-fglrx

However, I'm now stuck for ideas. Neither the default nor ATI drivers appear to work now, whereas in 8.10 I was able to run two screens absolutely fine.

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myxiplx (myxiplx) said :

Ok, quick update on my progress so far. I've done some reading around, and apparently the open source ATI drivers include no 3D support.

However, 9.04 still had visual effects set to Normal, which I believe means Compiz would be enabled. I set that to None, rebooted, and then tried to configure dual screen mode again. This time it worked.

However, it only appears to work when both monitors are at the same resolution (1280x1024 in this case). Any attempt to change the resolution on the second screen to the correct 1440x900 results in either that screen going blank, or both screens going blank and the computer rebooting.

So, what I've found so far is that:
- On an ATI Radeon x1950
- The proprietary drivers do not work at all
- ATI's new Catalyst 9.4 drivers don't support the x1950
- Dual Screen mode works if you disable all 3D effects
- Setting the two screens to different resolutions doesn't work at all.

Overall, this is a huge step backwards compared to 8.10. Since with 8.10 I could use either the proprietary or the open source drivers, I had 3D support in both, and I could also run dual screens quite happily (and at different resolutions on each when I used the open source driver).

Right now I'm focusing on finding a way to downgrade to 8.10.

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lolcat6 (iv0r) said :

Similar experience here. I upgraded to 9.04. I've got a ATI Technologies Inc RV280 [Radeon 9200 PRO]. Experienced similar problems when monitors were different resolution. Now working with two monitors that have the same resolution. Had problems with fglrx driver. Now using xserver-xorg-video-ati.

What is curious is that Firefox seems to be the only application that will start up in the second monitor (bless it). I've seen the info in question #56258. Using the 'Alt' key trick does not work.

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Nathan Flowers (nathan-flowers) said :

Well, I just installed a fresh ver of 9.04... I have an ATI 4870, Installed the recommended ati drivers form their site.
after the install I don't see any difference. I use the aticonfig in command line to enable dule head with horz monitor right (a quick example of the code not actualy the real code)
The other monitor just shows blank with an X for the mouse, it detecs the mouse movement on that monitor.
If I try to enable the display on that monitor it tells me that "command" can not be enabled while randr 2.1 is enabled.
I can't seem to figure out how to disable RandR 2.1.
Will post actual code later this evening.

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myxiplx (myxiplx) said :

Well, after my initial problems, I've found that the open source "radeon" drivers now work fine, even with 3D support for Compiz on my card. The only limitation I hit was that I had to turn off 'window decoration' in ccsm before desktop effects would enable.

The end result is that I'm now using both screens at their proper resolutions with an open source driver, with 3D support working fine (I can even play OpenArena).

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Nathan Flowers (nathan-flowers) said :

Can you post any code you used to get your multi monitors working? or did you use GUI management?
Can you post a how to? I know most of what you said is self explanatory. I just want to make sure I'm not missing a step.
Thanks in advance.

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myxiplx (myxiplx) said :

Well, it's been a while, and I've got a terrible memory so there may well be steps missing here. However, I believe the basics were simply:

# sudo apt-get remove --purge fglrx
# sudo apt-get install radeon

As I mentioned above, I had problems with compiz initially, so I would recommend turning off all desktop effects first via System -> Preferences -> Appearance.

I also had problems with Window effects to begin with (although they enabled fine later on), so I would be ready to turn off window decoration if you have any problems with compiz:

# sudo apt-get install ccsm

And then in the gui:
System -> Preferences -> CompizConfig Settings Manager
Scroll down to effects, and untick Window Decoration.