Fix mouse sensitivity (Razer Diamondback 3g)

After plugging in a Razer Diamondback 3g in Ubuntu 11.10 I found that the sensitivity was spectacularly high, and I was unable to edit it using gnome settings.

The fix is to manually edit xorg.conf to set a constant deceleration for the device in question.

sudo gedit /etc/X11/xorg.conf

Whether or not the file exists, simply append the following:

Section "InputClass"
     Identifier "mouse speed adjustment"
MatchIsPointer "on"
MatchProduct "Diamondback 3G"
Option "ConstantDeceleration" "2"
EndSection

Where MatchProduct will look for a device name containing what is specified. This can be found by running:

cat /proc/bus/input/devices

and scanning the resulting output for the name of the device in question.

The higher the number associated with ConstantDeceleration, the less sensitive the mouse will be.

Hope this helps.