22 Aug 2008, 12:49

Test drive KDE4.1 on Debian Lenny


The Debian KDE Maintainers recently released inofficial Backports of KDE4.1 for Debian Lenny for those who didn’t wan’t to use experimental packages or wait for lenny to become stable. I was waiting for this packages for a long time. Since I’ve used KDE 4.0 at work I did want to use it at home, too. But I did not want to break my system more than absolutly necessary and I didn’t like some of the shortcoming of KDE 4.0, so I had to wait. The 4.1 release looked very promising to me and so I did decide to give it a try. Many people told me not to use KDE 4.1 but I did really like KDE 4 since my first contact. Unfortunately there are known issues with KDE 4.1 and the proprietary Nvidia drivers which I use and the compositing features of KWin only work with TwinView and not Xinerama, so I did prepare myself to some hurdles. I want to give a short report of my experiences on KDE 4.1 on Debian GNU/Linux lenny. Basically I did follow the steps described on the Backports page:

  1. Add “deb http://kde4.debian.net/ lenny main” to the sources.list.
  2. aptitude update Then I did try to “aptitude install kde4”, but as the Backports page states, this didn’t work. So I had to clean up the dependency mess (aptitude -f install) and start with the minimal kde package aptitude install kde4-minimal and then install the modules one by one. At least one of them had unmet dependencies and couldn’t be installed but I hope those will be resolved soon.

When KDE4.1 was finally installed I re-installed kdm by aptitude install kdm and logged in for the first time. The startup took a rather long time - I guess all the initial confguration files were created (or whatever).

I soon realised that the KWin/Nvidia issues were really annoying so I did look for a solution. Fortunately there were already a lot of good hints on this. While trying to fix this I did notice that my Xinerama setup was not supported and I had to switch (back) to TwinView. I don’t remeber why I did use Xinerama instead of TwinView, but I suppose it did just work back then when I set up the two monitor configuration. So as for the performance issues: Depending on the hardware you have, there are a lot of possible bug-fixes. At first you should make sure that you use a recent release of the Nvidia drivers. I did use 177.67 (BETA) from Nvidia and sticked to the tweaks from Nvidia. I put my “nvidia-settings” command in a bash script inside “.kde4/Autostart”.

Below is a list of modifications I made to my xorg.conf. Please note that these are only the modifications I made to the xorg.conf, this is no complete configuration.

After this changes I restarted the X server and made a few small modifications to the KWin settings:

The result? My KDE4.1 desktop, full compositing features enabled, is blazing fast now!

Section "ServerFlags"
Option "Xinerama" "0"
Section "Extensions"
Option "Composite" "Enable"
Section "Device"
Identifier     "nvidia0"
Driver         "nvidia"
Option      "NoLogo" "True"
BusID       "PCI:1:0:0"
Screen      0
Option "HWcursor"
Option "CursorShadow"
Option "CursorShadowAlpha" "32"
Option "CursorShadowXOffset" "3"
Option "CursorShadowYOffset" "3"
Option "AllowGLXWithComposite" "True"
Option "TwinView" "True"
Option "TwinViewOrientation" "LeftOf"
Option "MetaModes" "1280x1024,1280x1024;1280x1024;1024x768,1024x768;800x600,800x600"
Option "SecondMonitorHorizSync" "UseEdidFreqs"
Option "SecondMonitorVertRefresh" "UseEdidFreqs"
Option "RenderAccel" "true"
Option  "UseEvents" "false"
Option "TripleBuffer" "1"
Option "DamageEvents" "1"
Option "BackingStore" "1"
Option "PixmapCacheSize" "70000"
Option "OnDemandVBlankInterrupts" "true"
Section "Screen"
Identifier     "Screen0"
Device         "nvidia0"
Monitor        "monitor0"
DefaultDepth    24
SubSection     "Display"
Depth       24
Modes      "1280x1024" "1024x768" "800x600" "640x480"
Option "AddARGBGLXVisuals" "True"
Option "DisableGLXRootClipping" "True"
Option "PixmapCacheSize" "1000000"
Option "AllowSHMPixmaps" "0"
Option "AddARGBGLXVisuals" "True"