Fglrx

AMD Catalyst (previous fglrx: FireGL and Radeon for X ) is the proprietary graphics driver for AMD/ATI graphic cards. The open source alternative is radeon.

Hardware detection
To choose the right driver, first detect the graphics card. You can use lspci for this task:

If you have an AGP card, also detect the chipset supporting AGP:

Hardware support

 * Force legacy driver when you have Radeon HD 2000 - 4000:
 * Mask >=ati-drivers-13.1 and >=xorg-server-1.13:

Kernel
You need USB support. Also you need to activate the following kernel options:

If you have an AGP card, enable AGP support:

If you use a hybrid system with Intel integrated video card, you should also activite KMS and Intel driver. Make sure raedon is disable.

Driver
Portage uses the variable VIDEO_CARDS for enabling support for various graphics cards in packages. Setting VIDEO_CARDS to fglrx will pull in the driver :

Check the USE flags of :

After setting this you want to update your system so the changes take effect:

acpid
Some cards need acpid running to handle events. See the ACPI article.

Initial setup
This will generate an initial xorg.conf which uses the fglrx driver:

If this command fails without error, copy the file to the default location:

Set the OpenGL driver to use fglrx:

Settings
The most comfortable way for most users is to use as a graphical UI to configure the driver.

Unexplained segmentation faults and kernel crashes
If you experience unexplained segmentation faults and kernel crashes with this driver and multi-threaded applications such as Wine set UseFastTLS in xorg.conf to either 0 or 1, but not 2.

External resources

 * X.Org Wiki