Black flickering on Ubuntu 8.04

Hi all, I'm new to using SL on Linux (and in fact I'm fairly new to using any Linux distro for desktop computing), and as such, I'm not sure if this is a common problem or not. Anyway, I downloaded the latest Linux client from SecondLife.com, and here's the details of my system:

OS: Ubuntu 8.04
CPU: AMD Athlon 1800+
RAM: 1.5 GB
GPU: ATI Radeon X800 256MB

I first tried running SL with the generic open source graphics drivers that Ubuntu provided, and suffice it to say, performance was rather poor. The screen would also flicker black every time I clicked on something, but that's no big deal.

Then I tried the latest proprietary graphics drivers, and performance was absolutely great (better than under WinXP on the same system ). However, the screen flickers black every second, or even more often if I have other applications running. SL is still entirely usable, but the flickering gets quite sore on the eyes! My best guess is that there is a bit of a battle going on between the windowing system and SL, and somehow the system blanks the entire display immediately after SL has rendered a frame.

Things I've tried so far to solve it:

* Closing all other applications (reduced the problem a little)
* Reducing to a single active workspace (no effect)
* Full-screen instead of windowed mode (no effect)
* Minimal graphics detail settings (no effect)
* Reducing texture memory usage in SL (no effect)
* Executing "sudo aticonfig --locked-userpages=off" as suggested in the readme (no effect)


Is there anything else I should be trying? I'm not sure if disabling some extensions will help this, but I am willing to give it a shot if necessary (although stability is otherwise great... I was using it for over 2 hours with hardly any other issues).


Thanks,
-Pedro

I have the same problem, and have not found a fix. I have installed Ubuntu on several different machines wth different cards and they all flicker.

I did, however, find a way to pull up the Advanced menu. The keystrokes <CTRL>+<ALT>+D minimize the current window in Ubuntu, but it is possible to change the trigger to <CTRL>+<ALT>+F or whatever combination you like. Go to Preferences>Keyboard Shortcuts and change the trigger to something else. Then you can bring up the Advanced menu.

The "black flickering" is caused by running Compiz Fusion (AKA, Desktop Effects), which are enabled by default on most newer video cards.

These can be disabled via:
System > Preferences > Appearance > Visual Effects > None


The downside to this is you'll lose your shiny effects, but at least SL will be usable.

Caveat: This bug affects all OpenGL-based applications running on the desktop when Compiz is present.

Good tip Sandar, I'll bear that in mind.

And thanks Jeffrey, I'll try disabling all the visual effects when I get home tonight.

The problem I have which appeared in the last few weeks or months, I dunno when. Is switching desktops, when going back to SL, it stays black (only inside the app window) for different lengths of time it seems. Sometimes 20 seconds. I hate that. Did not do it before.
Don't have compiz. Using Cool SL viewer.
Just thought Id mention it because it SHI*S me no end.

As far as I know, that's related to the update timing of the viewer. I have similar symptoms during task switching.

Disabling the visual effects worked, and SL now runs beautifully. Thanks very much Jeffrey!