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
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 restrict the free distribution of the X.org software, something that the X.org development team is not willing to do. So if your board is not supported, this may be the reason why.
It is difficult to specify minimum hardware requirements for running X, as this depends on a lot of external factors, how many graphical programs you are planning to run, what else is going on on your computer, and so on. But any computer sold in the last, say, 5 to 8 years should work just fine, and probably many older ones as well. You should check the documentation for X and verify that your particular card is supported before taking the plunge and purchasing expensive hardware. Benchmark rating comparisons for various video cards under X.org are posted to the Usenet newsgroups comp.windows.x.i386unix and comp.os.linux.misc regularly.
As a side note, one author's (Kalle's) tertiary personal Linux system is an AMD K6-2 with 128 MB of RAM and is equipped with a PCI Permedia II chipset card with 8 MB of DRAM. This setup is already a lot faster with respect to display speed than many workstations. X.org on a Linux system with an accelerated SVGA card will give you much greater performance than that found on commercial Unix workstations (which often employ simple framebuffers for graphics and provide accelerated graphics hardware only as a high-priced add-on).
Your machine will need at least 32 MB of physical RAM and 64 MB of virtual RAM (for example, 32 MB physical and 32 MB swap). Remember that the more physical RAM you have, the less frequently the system will swap to and from disk when memory is low. Because swapping is inherently slow (disks are very slow compared with memory), having 32 MB or more of RAM is necessary to run X.org comfortably. A system with 32 MB of physical RAM could run much more slowly (up to 10 times more slowly) than one with 64 MB or more.