Running Linux, 5th Edition - Matthias Kalle Dalheimer [320]
To fully understand the concept of window managers, you need to know that the window manager does not affect what the client application does within the window. The window manager is only in charge of painting the window decoration—that is, the frame and the buttons that let you close, move, and resize windows.
There can be only one window manager on any X server. Theoretically, it is even possible to completely do away with window managers, but then you would not be able to move windows around the screen; put a hidden window on top; or minimize, maximize, or resize windows unless the programs themselves provided this functionality.
Let's shortly mention the desktop environments again. A desktop environment such as KDE or GNOME is a collection of applications and tools with a common look and feel as well as many other common properties—for example, the menus of the applications could all be set up according to the same concepts. Desktop environments on X always need a window manager, as described earlier. Some desktop environments provide their own window manager (such as KWin in the KDE desktop environment), whereas others do not have their own window manager. It is up to the user to install a window manager of his or her choice.
Hardware Requirements
As of X.org Version 6.8.2, released in February 2005, the video chipsets listed in this section are supported. The documentation included with your video adapter should specify the chipset used. If you are in the market for a new video card, or are buying a new machine that comes with a video card, have the vendor find out exactly what the video card's make, model, and chipset are. This may require the vendor to call technical support on your behalf; vendors usually will be happy to do this. Many PC hardware vendors will state that the video card is a "standard SVGA card" that "should work" on your system. Explain that your software (mention Linux and X.org!) does not support all video chipsets and that you must have detailed information.
A good source for finding out whether your graphics board is supported and which X server it needs is http://www.x.org/X11R6.8.2/doc/RELNOTES3.html#9.
If you are unsure about which chipset you use, you can try to run
Xorg -configure
This will examine your hardware and create an initial configuration file that you can then tweak according to your needs.
It should be noted that the X.org project instituted an entirely new driver architecture some time ago, which is much more flexible than the old one and will enable more timely support of new graphics hardware.
Video cards using a supported chipset are normally supported on all bus types, including the PCI and AGP.
All these chipsets are supported in 256-color mode, some are supported in mono- and 16-color modes, and some are supported in higher color depths.
This list will undoubtedly expand as time passes. The release notes for the current version of X.org should contain the complete list of supported video chipsets. Please also always see the README file for your particular chipset.
Besides those chipsets, there is also support for the framebuffer device starting with the 2.2 kernel series via the fbdev driver. If your chipset is supported by the normal X server drivers, you should use those for better performance, but if it is not, you may still be able to run X by using the framebuffer. On some hardware, even the framebuffer device provides accelerated graphics.
One problem faced by the X.org developers is that some video card manufacturers use nonstandard mechanisms for determining clock frequencies used to drive the card. Some of these manufacturers either don't release specifications describing how to program the card, or require developers to sign a nondisclosure statement to obtain the information. This would obviously