After upgrade to this version (which includes the unstable and experimental version of the package), X
has become very slow. 2d operations incolve significant lag, and moving windows around on screen is
perceptible sluggish compared to previos versions of the package. The poor performance is also causing
perceptible flicker in terminals while typing.

I'm not sure how many chipsets are affected, but the card performance has fallen off enormously.

Mike

Which window / compositing manager is that with? Does it use OpenGL?

Which terminal emulator application is that with?

* Michel Dänzer <daenzer@debian.org> [110310 08:27]:

WM is Enlightenment DR17, from the e17 0.16.999.49898-1 Debian package.

Eterm - though I'm of the opinion that the terminal emulator isn't
actually relevant. The problem appears to be affecting any application
that moves substantial amounts of graphics data around - so scrolling a
large amount of text in a terminal window causes visible flicker.
Equally, rapidly moving a window around the desktop causes very obvious
lag as the X server struggles to keep up, with ghost images being left
around for a short period afterwards.

This happened after a dist-upgrade, so something ha clearly regressed
pretty severaly with my configuration. I've tried with the xorg.conf in
place, and also without any xorg.conf at all with the same results. I've
also tried with 2.6.32 and 2.6.37 kernels.

GL support is enabled, but the window manager does not have the
compositing module loaded. Performance with glxgears is hovering around
60 frames/sec, but that may be due to syncing to Vblank. I've not tried
much with 3d yet, as I mostly use 2d apps. Any suggestions as to how to
narrow it down would be gratefully received....

Mike

Hi,

Mike Brodbelt <mike@coruscant.demon.co.uk> (10/03/2011):

IIRC a coworker of mine had perf issues (under E) without compositing,
what if you enable it?

Correct. (glxgearsisnotabenchmarkbutyoucouldtrypassingvblank_mode=0throughtheenvironmentbutglxgearsisstillnotabenchmark)

KiBi.

Well, if it uses core X11 fonts, then text is rendered in software,
which could certainly explain at least some of the issues. If you're
using a non-anti-aliased font in the terminal, does switching to an
anti-aliased one improve terminal performance?

I'm afraid that's rather vague and doesn't ring any bells.

Then I don't suppose Option "ColorTiling" "off" helps, as I don't think
that could have been enabled with 2.6.32.

Basically, you need to try and narrow down further what exactly made
things worse for you. Is it the new X server or driver? ...

Though, if the bad performance is accompanied by high CPU usage of the X
server process, getting a profile with sysprof or oprofile might give an
idea of what's going wrong. Please make sure the xserver-xorg-core-dbg
and xserver-xorg-video-radeon-dbg packages are installed for this.

I've tried this again now with Xterm, using "xterm -fa 'Mono' -fs 8" as
the launch command line, which uses an anti-aliased font. There doesn't
appear to be any improvement.

Sorry - best description I could come up with. It's vaguely reminiscent
of moving from outline window moving to opaque window moving years ago,
when graphics cards were more underpowered than they are these days...

Aha. That appears to have cured it.

So, it looks like that option is the cause of a significant performance
drop, which affects the desktop feel quite a bit.

If there's anything more I can do to narrow this down further and help
it towards something useful to developers, I'm happy to test.

Thanks,

Mike

Odd. Maybe it's still falling back to software rendering for some other
reason.

Hmm, but I just double-checked, and tiling should only be enabled with
kernel >= 2.6.36. Why didn't 2.6.32 work better?


Have you tried if compositing works better?

Dear Maintainer,

   * What led up to the situation?
   * What exactly did you do (or not do) that was effective (or
     ineffective)?
   * What was the outcome of this action?
   * What outcome did you expect instead?

Since I upgraded from stable to testing I see serious performance regression w/ the driver though I would say other packages had its effect on the regression.
It is because I did upgrade by steps - starting w/ the packages I wanted before I chose completely to move from stable to testing.

The packages, after which upgrade to testing the regression was notable:

xserver-xorg-video-radeon
firmware-linux-free
firmware-linux-nonfree
libgl1-mesa-dri
libgl1-mesa-glx

Finaly, from 412 FPS (stable) the performance fell down to 44 FPS (testing) - metered with glxgears.
I know that the utily is not a proper tool for the metering yet IT can give some numbers that I would agree with - visually.