Xwindows very slow since recent update

[patter]

I have a desktop that has been installed & running linux very well for about 2 years, with intel graphics & a TFT screen. After a recent software update, with no hardware changes and retaining the old xorg.conf, X11 graphics performance has seriously slowed down. Switching between 2 full-screen X applications can take seconds to fully display.

The system's running Debian unstable with the following
kernel 2.6.26, xorg 7.4
00:02.0 VGA compatible controller: Intel Corporation 82865G Integrated Graphics Controller (rev 02)

I'm currently using the intel drivers in Xorg, if I reboot to use the intel framebuffer (video=intelfb:mode=1024x768-16) the framebuffer only loads at 640x480.

I've tried removing the xorg.conf file & booting from a few recent live CDs, but they don't help. The automatic X setup selects modes out-of-range for the monitor so that powers off, and using a framebuffer with any of them only gives a 640x480 display

I can't upgrade the kernel, this system locks hard if running 2.6.30.

xorg.conf

Section "ServerLayout"
  Identifier     "Default Layout"
  Screen         "Default Screen"
  InputDevice    "Generic Keyboard"
  InputDevice    "Configured Mouse"
EndSection

Section "Files"

  # path to defoma fonts
  FontPath     "/usr/share/fonts/X11/misc"
  FontPath     "/usr/X11R6/lib/X11/fonts/misc"
  FontPath     "/usr/share/fonts/X11/cyrillic"
  FontPath     "/usr/X11R6/lib/X11/fonts/cyrillic"
  FontPath     "/usr/share/fonts/X11/100dpi/:unscaled"
  FontPath     "/usr/X11R6/lib/X11/fonts/100dpi/:unscaled"
  FontPath     "/usr/share/fonts/X11/75dpi/:unscaled"
  FontPath     "/usr/X11R6/lib/X11/fonts/75dpi/:unscaled"
  FontPath     "/usr/share/fonts/X11/Type1"
  FontPath     "/usr/X11R6/lib/X11/fonts/Type1"
  FontPath     "/usr/share/fonts/X11/100dpi"
  FontPath     "/usr/X11R6/lib/X11/fonts/100dpi"
  FontPath     "/usr/share/fonts/X11/75dpi"
  FontPath     "/usr/X11R6/lib/X11/fonts/75dpi"
  FontPath     "/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType"
EndSection

Section "Module"
  Load  "bitmap"
  Load  "ddc"
  Load  "dri"
  Load  "extmod"
  #Load  "freetype"
  Load  "glx"
  Load  "int10"
  Load  "vbe"
  #Load  "shm"
EndSection

Section "InputDevice"
  Identifier  "Generic Keyboard"
  Driver      "kbd"
  Option      "CoreKeyboard"
  Option      "XkbRules" "xorg"
  Option      "XkbModel" "pc105"
  Option      "XkbLayout" "gb"
EndSection

Section "InputDevice"
  Identifier  "Configured Mouse"
  Driver      "mouse"
  Option      "CorePointer"
  Option      "Device" "/dev/input/mice"
  Option      "Protocol" "ImPS/2"
EndSection

Section "Monitor"
  Identifier   "Generic Monitor"
EndSection
Section "Device"
  Identifier  "ATI Technologies Inc Radeon Mobility M7 LW [Radeon Mobility 7500]"
  Driver      "intel"
  BusID       "PCI:0:2:0"
  #Driver   "fbdev"
EndSection

Section "Screen"
  Identifier "Default Screen"
  Device     "ATI Technologies Inc Radeon Mobility M7 LW [Radeon Mobility 7500]"
  Monitor    "Generic Monitor"
  DefaultDepth     16
  SubSection "Display"
    Depth     1
    Modes    "1024x768" "800x600" "640x480"
  EndSubSection
  SubSection "Display"
    Depth     4
    Modes    "1024x768" "800x600" "640x480"
  EndSubSection
  SubSection "Display"
    Depth     8
    Modes    "1024x768" "800x600" "640x480"
  EndSubSection
  SubSection "Display"
    Depth     15
    Modes    "1024x768" "800x600" "640x480"
  EndSubSection
  SubSection "Display"
    Depth     16
    #Modes    "1280x1024" "1152x864" "1024x768" "800x600" "640x480"
    Modes    "1024x768" "800x600" "640x480"
  EndSubSection
  SubSection "Display"
    Depth     24
    Modes    "1280x1024" "1152x864" "1024x768" "800x600" "640x480"
  EndSubSection
EndSection

Section "DRI"
  Mode         0666
EndSection

[sarlacii]

Hey Patter... have you had a look at dmesg and your X logs for errors? If not, that may be where to start.
Else, run top in a terminal when you change apps and look to see if something other than X is hogging CPU cycles.
It's just a start.
If you could also post exactly what was included in your "software update", that could help... since you report that is was only after the update that things went pear-shaped. Did you upgrade your entire distro? Or was is just a new application with some dependancies that you installed?
Thanks.

[zespo]

Hi

Have you solved your problem. I have exactly the same.

[reed9]

It's most likely the intel graphics drivers causing the problem.

These are Ubuntu guides but should be basically applicable.

New Ubuntu Intel Graphics Drivers ~ Web Upd8

Intel Graphics Performance Guide for Ubuntu 9.04 (Jaunty) Users|Ubuntu Geek