XFree86 Acceleration Architecture
In the X Window System, XFree86 Acceleration Architecture (XAA) is a driver architecture to make a video card's 2D hardware acceleration available to the X server. It was written by Harm Hanemaayer in 1996 and first released in XFree86 version 3.3. It was completely rewritten for XFree86 4.0. It was removed again from X.Org Server 1.13.
Most drivers implement acceleration using the XAA module. XAA is on by default, though acceleration of individual functions can be switched off as needed in the server configuration file (XF86Config or xorg.conf).
The driver for the ARK chipset was the original development platform for XAA.
In X.Org Server release 6.9/7.0, EXA was released as a replacement for XAA, as XAA supplies almost no speed advantage for current video cards. EXA is regarded as an intermediate step to converting the entire X server to using OpenGL.
References
- Information for ARK Logic Chipset Users: Acceleration (XFree86.org)
- XAA.HOWTO: This file describes how to add basic XAA support to a chipset driver (Egbert Eich, 23 April 2004)