Adjustments to the mouse tracking speed are availabe via the command line and allow for settings not accessbile via system preference pane.

Read the current speed with

defaults read -g com.apple.mouse.scaling

The maximum speed available via system preferences is 3. Writing a new value via the command line allows higher tracking speeds. NB, restarting the mac may be required to allow the changes to take effect.

defaults write -g com.apple.mouse.scaling 4

Ref: Speed up Mouse Tracking on Mac OS X at tylernichols.com