Ubuntu 8.10 has a very slow / sluggish graphics stack.

[Dean Mellas]

Ubuntu 8.10 seems to have a sluggish graphics stack. It seems to affect all applications, so it may be down in the X server, one or more of the APIs, or even the graphics card drivers, but I see the effects on all computers, regardless of the graphics card or application. All GUI windows seems to show snow as they fly open on the 3D desktop, but quickly stabilize. Same with 3D disabled, but stabilizes more quickly, almost unnoticeable. My own GUI Java applications show a significant amount of interactivity lag, not present in the earlier releases (8.04 or earlier). I see the same results in both the OpenJDK and the Sun packages, so I suspect the newest X server. Same effects on both GNOME and KDE. Also, same effects on openSUSE, for that matter.

Possibly related: In AVIDeMux on Ubuntu 8.10 all audio playback is unusably choppy yet final output saved to the hard disk seems to show no ill effects. I think this might be related.

[Paul Peacock (peacockpaul9)]

I was just considering posting regarding poor graphics response. Have just install kubuntu8.10 on my dell Inspiron 1520. Snowing/breakup only appears to happen on the first instance of a menu opening, thereafter whilst an app is open it doesn't seem to happen to that particular app. If I'm honest perhaps that's a subjective observation, if it will help I'll try to keep a log of exactly when it happens.

[Dean Mellas (dmellas)]

I would not have even reported the "snowing" effect, except that I think everybody can notice it on nearly any system, as opposed to the trouble I am experiencing with my own animations. I'm believe both are symptomatic of the same underlying problems.

And yes, once a "snowing" window (for any normal application) is completely open, after launch, everything works well, thereafter. One thing I didn't point out before (because I thought this might be impacted by the Graphics Card driver a particular system); on one system, I had to disable the 3D effects in order to see any of the menus or other GUI widgets in Mozilla Thunderbird. Collapsing the left-hand tree view and re-expanding it would "jog" the screen to update, but the next action somewhere else would make it disappear again. I had to disable 3D to use Thunderbird at all - but only on that one system with a high-end graphics card.

The REAL problem is with real-time graphics (and not necessarily video). I use the Java Swing APIs to draw imagery that needs to follow mouse movements in real-time (updating constantly). That works in earlier releases of Ubuntu (and other distros) but shows a propensity to lag far behind the mouse in Ubuntu 8.10 (and the similarly timed openSUSE 11.1). The demands of my apps just make it more obvious. The new X.org is probably slower or inefficient somewhere AND not working as well with some binary graphics drivers, either.

[Paul Peacock (peacockpaul9)]

Just speculation or conjecture on my part, but does this have any relation to
kernel priority scheduling? I seem to have noticed a general slowing down
in Kubuntu in this release... and happened upon some threads regarding
scheduling after googling processor throttling. Maybe the two are unrelated
and I'm barking up the wrong tree.
On Thursday 29 January 2009 21:31:11 Dean Mellas wrote:
> [Bug 322561] Re: Ubuntu 8.10 has a very slow / sluggish graphics stack.
> From:
> Dean Mellas <email address hidden>
> To:
> <email address hidden>
> Date:
> Thursday 21:31:11
>
> I would not have even reported the "snowing" effect, except that I think
> everybody can notice it on nearly any system, as opposed to the trouble
> I am experiencing with my own animations.  I'm believe both are
> symptomatic of the same underlying problems.
>
> And yes, once a "snowing" window (for any normal application) is
> completely open, after launch, everything works well, thereafter.  One
> thing I didn't point out before (because I thought this might be
> impacted by the Graphics Card driver a particular system); on one

[Dean Mellas (dmellas)]

As a matter of fact, a lot of updates came in yesterday. Several were for the PulseAudio system and addressed the underlying scheduling and priority issues for the audio service threads. So you may be onto something. In my original post I debated mentioning the audio trouble with AVIDeMux (because what would that have to do with X), but I just thought it seemed to be related (the way my system was behaving). I never imagined the scheduling or priorities might get screwed up. Now, I've noticed that CPU throttling, specifically, has been an issue for a while on Linux, but the latest releases I've tested went backwards, somehow, with some audio and specific graphics performance. I will now re-test the audio issues with the latest patches as see if that seems to be in the right direction, and note if I see any change in relation to the video.

[aesis05401 (aesis05401)]

This report has been sitting for a couple of months in the generic 'Ubuntu' bin. Have subsequent updates resolved the issues?

If not, we will need to identify a more specific way to quantify this issue such that a developer could use it as a starting point for research. As it stands, the reported issue could be related to effects packages, the desktop manager, xorg issues, or a misconfiguration of another resource such that the amount of resources available for rendering your desktop is less than those provided by a previous OS install/configuration.

The fact that your audio playback, GUI interactivity, and rendering quality are all being affected makes me think you may be experiencing a general resource issue. The fact that this resource issue was not present under previous installs would lead me to look into all effects settings first (especially if you are using compiz on your desktop).

I am marking this report 'Incomplete' pending an update on your status. If you are still experiencing issues please post an update and change the report status back to 'New.' If left as 'Incomplete' this report will expire after 60 days.

Thanks for the report, and best of luck.

[Dean Mellas (dmellas)]

The activity dropped and the status was changes. This was reactivated to include the latest information.

[Dean Mellas (dmellas)]

There were a lot of questions raised in the original report back in January. Here are updates....

I have been following the progress of another bug (288650) and noticed that running the Java VM with a suggested option as a workaround:

java -Dsun.java2d.pmoffscreen=false YourProgramGoesHere

dramatically reduces the realtime graphics interactivity lag in my Java Applications. I will test this again when the Jaunty RC comes out in a few days to see if I still need this switch.

As far as Audio problems that may or may not have been related (apparently not). The sound cleared up after I went against the recommendations and switched audio from ALSA to Pulse in AVIDeMux. Now, the audio drops out every second for a moment in playback, but that has no effect of the production results and affects no other applications. Recommending that fix for bug (321028) seems to have completely solved the problems for others, so I'll just test again on Jaunty.

The snowing effect remains; however. I will see if I can capture it if it still exists in Jaunty. It looks just like an image file displayed with the wrong rendering format or the wrong video configuration for a moment when an application first starts - but then clears up quickly.

[Dean Mellas (dmellas)]

I have confirmed that the sluggish graphics I reported here for Ubuntu 8.10 is gone in 9.04 today - specifically, the Java performance is restored. Neither have I experienced the "snowing" effect, also reported here.

So, I am unsure of the "official" way to close this bug report. There is no "fix" in for 8.10, but the problem is gone in the new, 9.04 release. Hopefully, someone on this bug's watch list knows the proper way to close it out.

I believe it is likely the result of the work on the graphics drivers (see bug 288650), but one of the posters there has reported some regressions in the last few days; however, those were in the daily releases between the Jaunty RC last week and Final release, today.

[Adil Arif (adisari06)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Due to the fact this wasn't truly a bug report because it did not specify a single regression, error, failure, or fault within a program but rather a generalization of the state of a particular stack in the Operating System, I will be marking this bug as Invalid.

On a lighter note, I am truly glad to see that the overall graphics stack has improved and provides for a more pleasant desktop user experience. This improvement will further increase our market-share. Please, if you encounter any more bugs report them here. Take care.