Provided by:
xserver-xorg-core_1.5.2-2ubuntu3_i386 
NAME
exa - new 2D acceleration architecture for X.Org
DESCRIPTION
EXA provides a simple API for video drivers to implement for 2D
acceleration. It is a module loaded by drivers, and is not intended to
be loaded on its own. See your driver’s manual page for how to enable
EXA
The EXA architecture is designed to make accelerating the Render
extension simple and efficient, and results in various performance
tradeoffs compared to XAA. Some options are available for debugging
performance issues or driver rendering problems. They are not intended
for general use.
Option "EXANoComposite" "boolean"
Disables acceleration of the Composite operation, which is at
the heart of the Render extension. Not related to the Composite
extension. Default: No.
Option "EXANoUploadToScreen" "boolean"
Disables acceleration of uploading pixmap data to the
freamebuffer. Default: No.
Option "EXANoDownloadFromScreen" "boolean"
Disables acceleration of downloading of pixmap data from the
framebuffer. NOTE: Not usable with drivers which rely on
DownloadFromScreen succeeding. Default: No.
Option "EXAOptimizeMigration" "boolean"
Enables an additional optimization for migration of destination
pixmaps. This may improve performance in some cases (e.g. when
switching virtual desktops with no compositing manager) but
causes corruption in others (e.g. when starting compiz).
Default: No.
Option "MigrationHeuristic" "anystr"
Chooses an alternate pixmap migration heuristic, for debugging
purposes. The default is intended to be the best performing one
for general use, though others may help with specific use cases.
Available options include "always", "greedy", and "smart".
Default: always.
AUTHORS
Authors include: Keith Packard, Eric Anholt, Zack Rusin, and Michel
Dänzer