Difference between revisions of "KDE"

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(Updates for KDE SC 4.6)
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Important features of the Arch Linux KDE SC in short:
Important features of the Arch Linux KDE SC in short:
* '''Split packages'''; for more Information see [[KDE_Packages|KDE Packages]] and [[DeveloperWiki:Splitting_KDE|Splitting KDE]].
* '''Split packages'''; for more Information see [[KDE_Packages|KDE Packages]] and [[DeveloperWiki:Splitting_KDE|Splitting KDE]].
* You can use different Phonon backends, like Gstreamer or Xine
* You can use different Phonon backends, like Gstreamer, Xine or VLC
* Meta packages ensure a smooth upgrade and emulate the old monolith packages for those who prefer them.
* Meta packages ensure a smooth upgrade and emulate the old monolith packages for those who prefer them.
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===Arch Linux notes===
===Arch Linux notes===
* KDEpim has seen no new release, please continue to use version 4.4.x until (or if) KDEpim 4.6 is released.
This release offers UPower, UDev and UDisks support that can be used instead of the deprecated HAL. For that, the hal package is no more a requirement of kdebase-workspace and can be removed from your system.
* Due to incompatibility with ruby 1.9, ruby kdebindings are not provided on the official repos.
* Webkit support in konqueror is provided by kwebkitpart
KDE PIM 4.6 is yet not available (will be released with the next minor release), so we will continue with the 4.4 series.
* KDM is now started by the kdm user
* Upstream removed five translations: csb, mai, mk, si and tg
Also, with the last Phonon update, the DEVs declared the Xine backend no longer maintained and it needs PulseAudio to work; you really should think to switch to the GStreamer or the VLC backend.
In case of any error, try using a new user account or (re)moving KDE's configuration which can be found at ~/.kde4 /tmp/kde- /var/tmp/kdecache-. Akonadi saves its data at ~/.config/akonadi and ~/.local/share/akonadi.
The removed packages are: kdegames-ksame, kdesdk-kbugbuster, kdeutils-okteta The new packages are: kdeaccessibility-kaccessible, kdegames-klickety, kdesdk-okteta, kdeutils-filelight, kdeplasma-addons-concontainments, kdeplasma-addons-runners-events

Revision as of 02:45, 27 January 2011

This template has only maintenance purposes. For linking to local translations please use interlanguage links, see Help:i18n#Interlanguage links.

Local languages: Català – Dansk – English – Español – Esperanto – Hrvatski – Indonesia – Italiano – Lietuviškai – Magyar – Nederlands – Norsk Bokmål – Polski – Português – Slovenský – Česky – Ελληνικά – Български – Русский – Српски – Українська – עברית – العربية – ไทย – 日本語 – 正體中文 – 简体中文 – 한국어

External languages (all articles in these languages should be moved to the external wiki): Deutsch – Français – Română – Suomi – Svenska – Tiếng Việt – Türkçe – فارسی

Template:Article summary start

Template:Article summary text Template:Article summary text Template:Article summary heading Template:Article summary text Template:Article summary heading Template:Article summary wiki Template:Article summary end

From KDE - KDE Software Compilation:

The KDE Software Compilation grew out of the history of the KDE Project. In its inception, KDE was formed to create a beautiful, functional and free desktop computing environment for Linux and similar operating system. At the time, these systems lacked a graphical user environment that could rival the offerings from the larger proprietary operating system vendors. KDE was created to fill this gap.
The KDE Software Compilation is the set of libraries, workspaces, and applications produced by KDE that share this common heritage, and continue to use the synchronized release cycle. Software may move in and out of this semi-formally defined collection depending on the particular needs of the contributors who are working on that software, with exceptions made to ensure that binary compatibility remains at the library level throughout any major release of the compilation.

From KDE - Getting KDE Software:

KDE software consists of a large number of individual applications and a desktop workspace as a shell to run these applications. You can run KDE applications just fine on any desktop environment. KDE applications are built to integrate well with your system's components. By using also KDE workspace, you get even better integration of your applications with the working environment while lowering system resource needs.



KDE 4.6 Software Compilation is the current major release of KDE that includes a number of improvements and bug fixes. The new Arch package set for KDE makes it possible to only install those applications you like.

Important features of the Arch Linux KDE SC in short:

  • Split packages; for more Information see KDE Packages and Splitting KDE.
  • You can use different Phonon backends, like Gstreamer, Xine or VLC
  • Meta packages ensure a smooth upgrade and emulate the old monolith packages for those who prefer them.

Important hints for upgraders:

  • Always check if your mirror is up to date.
  • pacman will ask you to replace all kde packages with kde-meta packages.
  • Do not force an update. If pacman complains about conflicts please file a bug report.
  • You can remove the meta packages and the sub packages you do not need after the update.
  • If you do not like split packages just keep using the kde-meta packages.
Information about upstream changes are be available here

Arch Linux notes

This release offers UPower, UDev and UDisks support that can be used instead of the deprecated HAL. For that, the hal package is no more a requirement of kdebase-workspace and can be removed from your system.

KDE PIM 4.6 is yet not available (will be released with the next minor release), so we will continue with the 4.4 series.

Also, with the last Phonon update, the DEVs declared the Xine backend no longer maintained and it needs PulseAudio to work; you really should think to switch to the GStreamer or the VLC backend.

In case of any error, try using a new user account or (re)moving KDE's configuration which can be found at ~/.kde4 /tmp/kde- /var/tmp/kdecache-. Akonadi saves its data at ~/.config/akonadi and ~/.local/share/akonadi.

The removed packages are: kdegames-ksame, kdesdk-kbugbuster, kdeutils-okteta The new packages are: kdeaccessibility-kaccessible, kdegames-klickety, kdesdk-okteta, kdeutils-filelight, kdeplasma-addons-concontainments, kdeplasma-addons-runners-events


Full install

To install the entire KDE set, first fully upgrade your system:

# pacman -Syu

and then:

# pacman -S kde phonon-xine


# pacman -S kde-meta phonon-xine
Note: Learn about the difference between kde and kde-meta packages in the KDE Packages article.

If you need language files:

# pacman -S kde-l10n-yourlanguagehere

e.g. kde-l10n-de, for the German language.

Note: KDE 4.x is modular; you can install your preferred KDE applications without having to install an entire set of packages. See KDE Packages for more information.

Gamin, an extension of the file alteration monitor (fam) project, is more actively developed than fam, and will be useful for reflecting real-time changes in the filesystem.

Install with:

# pacman -S gamin

Minimal install

If you want to have a minimal installation of the KDE SC, here is an example:

# pacman -S kdebase kde-l10n-yourlanguagehere phonon-xine

Starting KDE

Add dbus to your DAEMONS array, to invoke it on boot.

DAEMONS=(syslog-ng dbus networkmanager alsa crond)

If you need to start it without rebooting:

# /etc/rc.d/dbus start

Starting KDE depends on your preferences. Basically there are two ways of starting KDE. Using KDM or xinitrc.

Using KDM (KDE Display Manager)

It is highly recommended to get familiar with the full article concerning display managers, before you make any changes. See also KDM Wiki page.

Starting KDM as a daemon

Add "kdm" (without the quotes) to daemons array in Template:Filename

DAEMONS=(syslog-ng dbus network crond ... kdm)

Starting KDM through /etc/inittab [preferable]

Edit Template:Filename and comment out:



#x:5:respawn:/usr/bin/xdm -nodaemon

Then uncomment:



x:5:respawn:/usr/bin/kdm -nodaemon
Note: In both methods KDM loads Xorg automatically.

Using xinitrc

The meaning and usage of xinitrc is very well described here.

Edit Template:FilenameTemplate:FilenameTemplate:Filename. Then uncomment:

exec ck-launch-session startkde 

After a reboot or/and login, each execution of Xorg (startx or xinit) will start KDE automatically.

Warning: By doing this you may have restart/shutdown functions enabled in your KDE menu.
Note: If you want to start Xorg at boot, please read Start X at boot article.


Note: Configuring KDE is primarily done in 'System Settings'. There are also a few other options available for the desktop with 'Desktop Settings' when you right click the desktop.

For other personalization options not covered below such as activities, different wallpapers on one cube, etc please refer to the Plasma wiki page.


How to set up the KDE desktop to your personal style; use different Plasma themes, window decorations and icon themes.

Plasma Desktop

Plasma is a desktop integration technology that provides many functions from displaying the wallpaper, adding widgets to the desktop, and handling the panels or "taskbar".


Plasma themes can be installed through the Desktop Settings control panel. Plasma themes define how your panels and plasmoids look like. If you like to have them installed system-wide, themes can be found in both the official repositories and AUR.


Plasmoids are little scripted or coded KDE apps that enhance the functionality of your deskop in a yet very pleasing way, based on the Plasma technology of KDE. You are able to display system-critical information like left over disk space or monitor/modify your network connection. It also allows all kinds of other widgets, like displaying the weather, a widget for easily pasting images to a pastebin website, or having collections of virtual folders "folderview". Just to name a few.

The easiest way to install more widgets is by left-clicking onto a panel or the desktop:

Add Widgets -> Get new Widgets -> Download Widgets

You should be aware that these widgets are not created officially by KDE developers. Most of them are just people who wanted to script one (easily) to suit a need they had.

It may be of interest to you that many different widget types are supported (not just our own "plasmoids" or widgets). Plasma can use all kinds of widgets, from MacOSX widgets, Microsoft Windows Vista/7 widgets, Google Widgets, and even the old system - SuperKaramba - widgets. You should however, prefer Plasma widgets to other ones, since they provide more thorough integration and are prepared to be on the KDE desktop.

This will present a nice frontend for kde-look.org and allows you to (un)install or update third-party widgets with just one click. They are also available in the repositories.

Note: The widgets provided via KHNS (KHotNewStuff, what you just used to download widgets) does not/cannot grant the ability to install third-party widgets written in C++ since nearly each one requires different setup techniques, etc. and is thus difficult/impossible to automate. In other words, there could theoretically be useful widgets out there that you cannot try.

One thing to keep in mind, is that when a third-part developers creates a C++ widgets which has severe bugs in it, it could potentially bring down the Plasma process (crashing it). Scripted ones are sandboxed and this cannot happen. If it does crash - no worries, just remove the widget.

Window Decorations

Window decorations can be changed in

System Settings -> Application Appearance -> Style

There you can also directly download and install more themes with one click and some are available on AUR.

KDE 4 Theme Integration with GTK Applications

To better integrate GTK and KDE 4 themes, you can use QtCurve

 pacman -S qtcurve-gtk2 qtcurve-kde4 gtk-kde4

or oxygen-gtk

 pacman -S oxygen-gtk

or you can download a GTK theme that matches your version of KDE here. This theme comes closer to the original Oxygen and is updated frequently.

Automatic procedure

To change the GTK theme to QtCurve or something else a few applications are available:

 pacman -S lxappearance
 pacman -S gtk-theme-switch2
 pacman -S gtk-chtheme

Then change the theme of your choice in the respective application:

Manual procedure

To manually change the GTK theme to QtCurve, you need to create the file Template:Filename with the following content:

include "/usr/share/themes/QtCurve/gtk-2.0/gtkrc"
include "/etc/gtk-2.0/gtkrc"

style "user-font"
    font_name="Sans Serif"
widget_class "*" style "user-font" 

Then you need to create the symbolic link Template:Filename:

ln -s .gtkrc-2.0-kde4 .gtkrc-2.0

If you want also specify a font, you can add (and adapt) the following line to the file:

 gtk-font-name="Sans Serif 9"

If you're using Oxygen icons and want a consistent look in GTK open/save dialogs, you can install an oxygenrefit2 icon theme from AUR and set it as your GTK icon theme. Add the theme to the Template:Filename file or you can use lxappearance and set it.


There are also a couple GTK themes built on the gtk-kde42-oxygen-theme Oxygen style that can also do this.

Icon Themes

Not many full system icons themes are available for KDE 4. You can open up System Settings > Application Appearance > Icons and browse for new ones or install them manually. Many of them can be found on kde-look.org.

Arch Linux Logo Icon in Kicker menu

Right-Click on the Kicker menu button, press "Application launcher settings" and then press the icon on the right. Then you may choose Arch Linux icon or any other icon that will replace the default one.

Alternatively, install archlinux-themes-kde from extra and select the Arch icon theme in System Settings->Application Appearance->Icons.


If by default, the fonts in KDE look poor, try installing the ttf-dejavu and ttf-liberation packages. After the installation, be sure to log out and back in. You should not have to modify any settings in the "Fonts" panel of the KDE System Settings application.

If you have personally set up how your Fonts render, be aware that System Settings may alter their appearance. When you go System Settings > Appearance > Fonts System Settings will likely alter your font configuration file (Template:Filename). There is no way to prevent this but if you set the values to match your Template:Filename file the expected font rendering will return (it will require you to restart your application or in a few cases for you to have to restart your desktop). Note too that Gnomes' Font Preferences will also do this if you use both desktop environments.

Space efficiency

KDE is often critizised for being bloated. The user might get this perception from seeing many toolbars and pretty big scaled icons in the applications. One thing that improved the situation was the new Kwin-Theme that came with KDE SC 4.4.* with the more elegant buttons that one can also resize. KDE Apps allows to hide many toolbars, menubars and statusbars.

All sorts of *bars

Most toolbars of a program can be removed in the menubar-entry "Settings". There you often can hide the statusbar and often all toolbars. The last step should be to remove the menubar itself via Ctrl + M. If you do not want to remove any bars you can still make them smaller or remove the text via:

System-Settings -> Appearance -> Style -> Tab "Finetuning" ->  "Main toolbar text", "secondary toolbar text"

Since most aspect ratios of modern flat screens are wider than 4:3 it could be reasonable to put the toolbar at the left or right of a window to artificially stretch windows more to the monitors aspect ratio.


There are also some settings and modifications you can apply to your plasmoids to make KDE less space wasting. For example, the "Digital Clock" wastes more space than the "Analogue Clock". The little plasma icon ("Cashew") that one can see in the panel can be hidden by locking the widgets via rightklicking onto the panel. If you have got many tasks in your task-manager you should consider using Smooth-tasks. This alternative task-manager allows you to just display the icons of a task thus using less space but still maintaining the ability of the user to distinguish the different tasks.

Install smooth-tasks from the AUR.

After installing and substituting it with the original task-manager you should have a deep look at the settings since they are much broader. one way of using the features of smooth-tasks could be to only display the icons of tasks and move the panel to the left or right of the screen. This is most usefull on widescreens. On very small screens it could be reasonable to set the bottom-panel to auto-hide completely. For netbooks there exists a special form factor to make a better use of the screen:

System-Settings -> Desktop -> Workspace -> Form factor

The windows decorations can also be resized by making the buttons in the decoration smaller thus making the whole top border smaller:

System Settings -> Appearance -> Windows -> Button size

You could also remove the side-border of all windows via:

System Settings -> Appearance -> Windows -> Border size


NetworkManager support has been added in KDE SC. See NetworkManager for more information.


Tip: Use the Cups web interface for faster configuration.

The printers are configured in this way can be found in applications KDE.

You can also choose the printer configuration through Systemsettings -> Printer Configuration. To use this method, you must first install the packages:

# pacman -S kdeadmin-system-config-printer-kde cups

Samba/Windows support

If you want to have access to Windows services:

pacman -S samba

You may then configure your Samba shares through

 System Settings > Sharing > Samba

KDE Desktop Activities

KDE Desktop Activities are Plasma based "virtual desktop"-like set of Plasma Widgets where you can independently configure widgets as if you had more than one screens/desktops. Since KDE 4.5, the feature of changing Desktop Activities has been simplified.

On your desktop, click the Cashew Plasmoid and on the pop-up window press "Activities".

A plasma bar will appear at the bottom of the screen which presents you the current Plasma Desktop Activities which exist. You can then navigate between them by pressing their correspondent icon.


KDE has integrated Powersaving service called "Powerdevil Power Management" that may adjust the powersaving profile of the system or/and the brightness of the screen (if supported).

How to enable generic powersaving

Navigate to Systemsettings > Power Management In Profile Management, in "When AC adaptor is plugged in" (or the battery option) choose "Powersave" In "Edit Profiles" > "Powersave", tick the "Enable System power saving", and then press apply.

How to enable Cpufreq based powersaving

Since KDE 4.5, Powerdevil doesn't handle CPU power schemes through Cpufreq. CPU scaling is defined by the hardware and/or kernel "ondemand" governor power scheme and that's the official way to have the system's power management handled, according to the guidelines by the kernel power-management devs.

Note: Despite the claim in the link above, it seems that CPU does not scale without cpufreq. Also, in Arch the default governor is "performance" and not "ondemand", so the user still needs to install the cpufrequtils package and add the "cpufreq_ondemand" module in the modules array in rc.conf.

You can easily use the desired governors through the Solid Device Framework.

In order to do that, follow these steps:

1. Install cpufrequtils

pacman -S cpufrequtils

and make sure you have your CPU's cpufreq module loaded. For more information on this, visit this article.

2. Then, in System Settings > Power Management, go to "Edit Profiles" > "Powersave", and make sure that "Enable system power saving" is enabled in the "CPU and System" tab.

After that, type the following command in the "When loading profile execute" text box:

solid-powermanagement set cpufreq ondemand

3. Now select the "Performance" profile and type this command in the "When loading profile execute" text box:

solid-powermanagement set cpufreq performance

You don't have to enable the "Enable System power saving" check box for this profile.

System Administration

Set keyboard layout in order switch language inputs

In order to do that, navigate to

   System Settings > Input Devices > Keyboard

There you may choose your keyboard model at first.

Note: It is preferable that, if you use Evdev, that means Xorg automatic configuration for keyboards, you should choose "Evdev-managed keyboard".

In the "Layouts" tab, you choose the languages you may want to use by pressing the "Add Layout" button and therefore the variant and the language. In the "Advanced" tab, you can choose the keyboard combination you want in order to change the layouts in the "Key(s) to change layout" sub-menu.

Terminate Xorg-server through KDE system settings

Navigate to

   System Settings > Input Devices > Keyboard > Advanced (tab) > "Key Sequence to terminate X server" submenu

and tick the checkbox.

Desktop Search and Semantic Desktop

Most users who freshly install KDE are wondering what functionality the following four pieces of software are able to offer. Most features are still somehow hidden under the hood and yet not many applications featured in the KDE SC are using these interfaces. This capter intends to first explain the features and then convince the user of the power these tools offer once properly integrated into KDE. The following sections are more or less a roughly shortened version of this blogpost.


Soprano is a library for QT that is able to process RDF data. This is semantic data. Semantic data is a special kind of metadata which is much more flexible than metadata you might know from MP3-Tags or Meta-Tags in HTML since RDF data more resembles the structure of a spoken sentence, thus allowing a much wider field of ways dealing with them. Soprano stores semantic data in a backend and allows low level access to this data.


Nepomuk is somehow the glue between Soprano and the KDE Desktop and thus the user. Nepomuk allows to tag the files with various entries and offers an API for the applications featured in KDE SC. It is enabled by default. Nepomuk can be turned on and off in

System Settings -> "Advanced" Tab -> Desktop Search

Nepomuk has to keep the trace of a lot of files, because of that is recommended to increase the number of files that can be watched with inotify, to do that:

sysctl fs.inotify.max_user_watches=524288

To do it persistant:

echo "fs.inotify.max_user_watches = 524288" >> /etc/sysctl.conf

And restart Nepomuk.


Akonadi is one of the ways of getting data into Nepomuk. Its intention is to gather all kinds of PIM data from KMail, KAdressbook or Kopete. It collects chat contacts, email adresses, email attachments and email contents. First of all it feeds Nepomuk with this data but moreover it provides a centralized accesspoint for all this data.

Strigi Search

Strigi is another way of feeding data into Nepomuk. It preverably indexes the users home-folder. Indexing means that it not only gathers filenames but also information about your music collection or tagged downloads you did with Kget. The Strigi search is also integrated into KDEs launcher which can be accessed via: Template:Keypress + Template:Keypress

By default, Dolphin has a search bar on top-right where you may type what you want to be found from Strigi's index.

Note: Strigi has implications for resource usage on your computer - CPU, memory, disk access, disk space, battery life. If Strigi is too resource-hungry for you, you can turn it off in "System Settings > Advanced > Desktop Search".

Strigi folder indexing can be configured in:

System Settings -> "Advanced" Tab -> Desktop Search

KDM (KDE Desktop Manager)

KDM Xserver file

An example configuration for KDM can be found at /usr/share/config/kdm/kdmrc. See /usr/share/doc/HTML/en/kdm/kdmrc-ref.docbook for all options.

Configuring KDM

You can visit System Settings > Login Screen and make your changes. Whenever you press "Apply", a KDE Polkit authorisation window appears which will ask you to give your root password in order to finish the changes.

Problems while Configuring KDM as a user

If you seem not to be able to KDM settings when launching System Settings as user, press

Template:Keypress + Template:Keypress

and type

 kdesu systemsettings

In the pop-up kdesu window, enter your root password and wait for System Settings to be launched.

Note: Since you have launched it as root, be careful when changing your settings. All settings configuration in root-launched System Settings are saved under /root/.kde4 and not under ~/.kde4 (your home location).

In the System Settings window, go to Login Screen.


What is Phonon?

Phonon is the multimedia API for KDE 4. Phonon was created to allow KDE 4 to be independent of any single multimedia framework such as GStreamer or xine and to provide a stable API for KDE 4's lifetime. It was done for various reasons: to create a simple KDE/Qt style multimedia API, to better support native multimedia frameworks on Windows and Mac OS X, and to fix problems of frameworks becoming unmaintained or having API or ABI instability.

from Wikipedia.

Phonon is being widely used within KDE, for both audio (e.g., the System notifications or KDE audio apps) and video (e.g., the Dolphin video thumbnails).

Which backend should I choose?

You can choose between various backends, like Gstreamer, Xine ( phonon-xine ) or VLC ( phonon-vlc ).

Using WebKit in Konqueror

What is WebKit?

WebKit is an open source browser engine developped by Apple Inc. It is used by Safari and Google Chrome. WebKit is a derivative from the KHTML and KJS libraries and contain many improvements.

How to use in konqueror

It is possible to use WebKit in Konqueror instead of KHTML. First install the kwebkitpart package :

 pacman -S kwebkitpart

Then execute the following command

 keditfiletype text/html

In the window that opens go to the "Embedding" tab. Move the entry "WebKit" up to the top of the list and then hit the "OK" button and restart Konqueror.


KHotkeys issue

Ιf khotkeys does not work, make sure you have a fully updated system first. You can also create ~/.kde4/Autostart/reloadkhotkeys.sh with contents

(sleep 3 && qdbus org.kde.kded /modules/khotkeys reread_configuration) &

and then do a

chmod u+x ~/.kde4/Autostart/reloadkhotkeys.sh

then logout & login.

Enabling back/forward mouse buttons in Konqueror and Dolphin file managers

First, you must install xautomation which can be downloaded from [AUR] and xbindkeys, which can be installed using Pacman.

Next, create a text file named .xbindkeysrc and save it to your home directory. The content of the file should be:


Now create an autostart entry in /home/user_name/.kde4/Autostart named xbindkeys.desktop containing the following code:


Now just reboot your computer and you should have back/forward mouse button functionality in Dolphin and Konqueror.

Enabling thumbnails under Konqueror and Dolphin file managers

For thumbnails of videos in konqueror and dolphin:

 # pacman -S kdemultimedia-mplayerthumbs


 # pacman -S kdemultimedia-ffmpegthumbs

Suspend to Disk/Ram not working

If suspend to disk/ram does not work the be sure hal is running, also make sure you are in the power group (remember to logout) Also, if you are starting KDE with startx try adding ck-launch-session to the .xinitrc, as so:

# ~/.xinitrc
# Executed by startx (run your window manager from here)
# exec gnome-session
exec ck-launch-session startkde
# exec startxfce4
# ...or the Window Manager of your choice

This is done automatically with kdm.

Graphical related issues

Low 2D desktop performance (or) Artifacts appear when on 2D

GPU driver problem

Make sure you have the proper driver for your card installed, so that your desktop is at least 2D accelerated. Follow these articles for more information: ATI, NVIDIA, Intel for more information, in order to make sure that everything is all right. The open-source ATI and Intel drivers and the proprietary (binary) Nvidia driver should theoretically provide the best 2D and 3D acceleration.

The Raster engine workaround

If this doesn't solve your problems, maybe your driver doesn't provide a good XRender acceleration which the current Qt painter engine relies on by default. You can change the painter engine to software based only by invoking the application with the "-graphicssystem raster" command line. This rendering engine can be set as the default one by recompiling Qt with the same as configure option, "-graphicssystem raster". The raster paint engine enables the CPU to do the majority of the painting, as opposed to the GPU. You may get better performance, depending on your system. This is basically a work-around for the terrible Linux driver stack, since the CPU should obviously not be doing graphical computations since it is designed for fewer threads of greater complexity, as opposed to the GPU which is many threads but lesser computational strength.

Since Qt 4.7+, recompiling Qt is not needed. Simply export QT_GRAPHICSSYSTEM=raster, or "opengl", or "native" (for the default). Raster depends on the CPU, OpenGL depends on the GPU and high driver support (it's buggy and highly in development, so I wouldn't expect it to work), and Native is just using the X11 rendering (mixture, usually).

The best and automatic way to do that is to install kcm-qt-graphicssystem from AUR and configure this particular Qt setting through

 System Settings > Qt Graphics System

For more information, consult this KDE Developer blog entry and/or this Qt Developer blog entry.

Konsole is slow in applications like vim

This is a problem that is caused by slow glyph rendering. You can solve this by switching to a scalable font like Bitstream Vera Sans Mono.

Low 3D desktop performance

KDE begins with desktop effects enabled. Older cards may be insufficient for 3D desktop acceleration. You can disable desktop effects in

System Settings > Desktop 

or you can toggle desktop effects with Template:Keypress + Template:Keypress + Template:Keypress

Note: You may encounter such problems with 3D desktop performance even when using a more powerful graphics card, but using catalyst proprietary driver (fglrx). This driver is known for having issues with 3D acceleration. Visit the ATi Wiki page for more troubleshooting.

Desktop compositing is disabled on my system with a modern Nvidia GPU

Sometimes, KWin may have settings in it's configuration file (kwinrc) that may cause a problem on re-activating the 3D desktop OpenGL compositing. That could be caused randomly (for example, due to a sudden Xorg crash or restart, and it gets corrupted), so, in case that happens, delete your ~/.kde4/share/config/kwinrc file and relogin. The KWin settings will turn to the KDE default ones and the problem should be probably gone.

Flickering in fullscreen when compositing is enabled

According to https://fedoraproject.org/wiki/KDE/How_to_reduce_fullscreen_flicker :

Press Alt+F2 and run:

    kwriteconfig --file kwinrc --group Compositing --key UnredirectFullscreen --type bool false

Apply the changes by pressing Alt+F2 and running:

    qdbus org.kde.kwin /KWin reconfigure

This forces KWin not to use window unredirection but can affect performance of fullscreen OpenGL applications when desktop effects are enabled. Desktop effects can be suspended to prevent performance issues (press Alt+Shift+F12) before running such applications.

See https://bugs.kde.org/show_bug.cgi?id=177495

Sound problems under KDE

ALSA related problems

Note: First make sure you have alsa-lib and alsa-utils installed.
"Falling back to default" messages when trying to listen to any sound in KDE

When you encounter such messages:

The audio playback device <name-of-the-sound-device> does not work.
Falling back to default

Go to

System Settings > Multimedia

and set the device named "default" above all the other devices in each box you see.

I cannot play mp3 files when having Gstreamer backend in Qt Phonon

That can be solved by installing gstreamer0.10-plugins

 pacman -S gstreamer0.10-plugins

You can also change the backend used by Phonon, by installing the phonon-xine

 pacman -S phonon-xine

if you encounter problems that are not solved after installing gstreamer plugins. Then choose Xine in

 System Settings > Multimedia > Backend (tab)

(it may have been autoselected after installing phonon-xine)

No KDE system notifcations sounds with phonon-xine

If you get no sounds with any system notifcation in general and you are using phonon-xine then you need to install the speex package, an optional dependence of xine-lib.

 pacman -S speex
Amarok "waits" before playing any track

If you have encountered this error, the problem is backend specific. In order to solve this problem, change Amarok's backend from gstreamer to xine.

Phonon with Xine backend and ALSA devices

If using Phonon with the Xine backend, not all ALSA devices in /etc/asound.conf or ~/.asoundrc (or the default ALSA device) may show or be available.

Symptoms of the problem:

  • ALSA devices do not appear in System Settings > Multimedia > Phonon
  • speaker-test yields Error -2, "No such file or directory"
  • aplay yields a file or directory not found error

Problem and workaround documented on the KDE Phonon Wiki

OSS4 related problems

If you have OSS4 installed and encounter any problems you should be aware that developers of Kmix are still integrating OSSv4 support. There is an AUR package that is still experimental. Arch uses phonon with the Gstreamer backend that should work for most applications. Alternately you could try phonon with Xine.

Arch linux specific packaging issues

Due to some upgrades on the packages or a newer versioned pacman with bugs (pft, like there are any ;) there could be some problems during upgrading. Please read the sections below, if you have a problem.

I wanted a minimal installation of KDE. After I installed some packages and logged in KDE, there are no panels

If you wanted a minimal installation of KDE, logged in, heard the login sound but nothing else happened, you may not have installed the Plasma binaries. These are included in


Install this package and restart Xorg.

I want a fresh installation of KDE for my system. What should I do?

Just rename the settings directory of KDE (just in case you'll want to go back to your original settings):

mv ~/.kde4 ~/.kde4-backup

Plasma desktop behaves strangely

Plasma issues are usually caused by unstable plasmoids or plasma themes. First, find which was the last plasmoid or plasma theme you had installed and disable it or uninstall it.

So, if your desktop suddenly exhibits "locking up", this is likely caused by a faulty installed widget. If you cannot remember which widget you installed before the problem began(sometimes it can be an irregular problem), try to track it down by removing each widget until the problem ceases. Then you can uninstall the widget, and file a bug report (bugs.kde.org) only if it is an official widget. If it is not, I recommend you find the entry on kde-look.org and inform the developer of that widget about the issue (detailing steps to reproduce, etc).

If you cannot find the problem, but you do not want all the KDE settings to be lost, do:

 rm -r ~/.kde4/share/config/plasma*

This command will delete all plasma related configs of your user and when you will relogin into KDE, you will have the default settings back. You should know that this action cannot be undone. You ought to create a backup folder and copy all the plasma related configs in it.

Other KDE projects

KDE unstable (snapshot)

Unofficial kde-unstable

The member ProgDan has created a repo where he uploads the testing KDE packages when a new upstream snapshot is out. You may visit this topic for more information.

Semi-official kde-unstable

When KDE is reaching beta or RC milestone, KDE "unstable" packages are uploaded to the [kde-unstable] repo.

You may add it by adding:

Include = /etc/pacman.d/mirrorlist

in Template:Filename

They stay there until KDE is declared stable and passes to [extra].

Make sure you make bug reports if you find any issues.

Read this section in the wiki as well.

KDE Legacy

Unofficial community repository for KDEmod3

From the release of KDE 4.0, the developers dropped support for KDE 3.5.x. Nevertheless you can still use KDE 3.5.x through a project called kdemod3 In this thread you may find info on a rebuild of the unsupported KDEmod3.

Warning: KDE 3 is no longer maintained and supported by the KDE developers. KDEmod3 is no longer maintained by the Chakra Projects developers. Use it on your own risk, regarding any bugs, performance issues or security risks.


Distro and Upstream bug report

It is preferrable that if you find a minor or serious bug, you should visit the Arch Bug Tracker or/and KDE Bug Tracker in order to report that. Make sure that you be clear on what you want to report.

If you have any issue and you write about in on the Arch forums, first make sure that you have FULLY updated your system using a good sync mirror (check here) or try reflector.

KDE 4 config files are usually located at


and for app-specific configs


External Links