the Hive Mind | Main / MouseSensitivity

Mouse Sensitivity / Acceleration

In the context of OS settings, the following terms usually apply:

Sensitivity, resolution, or speed is the constant factor relating physical distance to pixels. This can be tuned to match the sensitivity of your mouse.

Acceleration is the factor to change speed by when the mouse is moved faster than a threshold speed. Often set as a ratio with separate numerator and denominator. Values between 0 and 1 cause deceleration. A value of 1 disables acceleration. Some FPS gamers dislike acceleration because it decouples the 1:1 relationship of pixels to physical distance. However, acceleration can help greatly with very fine pointer movements, such as sniping or grabbing the edge of a window. Windows has a hard on/off acceleration switch labeled enhance pointer precision. Additional steps may be required to fully remove acceleration on Windows.

Acceleration Threshold is the speed past which the mouse must move to enable acceleration. Often the time interval is fixed and this value is a pixel count past which the pointer must move in that short interval.

Linux Configuration

Mouse settings can be controlled through the GUI tool of your choice, but if this is not sufficient, the mouse can be configured through a file in /etc/X11/xorg.conf.d/.

Advice on choosing acceleration values can be found here. Advice on using slightly more advanced features to greatly enhance usability can be found here.

The following example shows my preferred configuration for my Razer Diamondback 3G in the file /etc/X11/xorg.conf.d/52-mouse.conf.

Section "InputClass"
	Identifier "Razer Mice"
	MatchIsPointer "yes"

	# All following directives are optional.

	# Only apply to Razer mice
	MatchVendor "Razer"

	# Choose a smooth polynomial acceleration function
	Option "AccelerationProfile" "2"

	# Divide absolute sensitivity by:
	Option "ConstantDeceleration" "2"

	# Acceleration Ratio
	Option "AccelerationNumerator" "5"
	Option "AccelerationDenominator" "3"

	# Pixel value Acceleration Threshold
	Option "AccelerationThreshold" "4"
EndSection

Values for MatchVendor and MatchProduct (both of which are optional) are taken from udev's VENDOR and NAME fields, respectively. Not all devices report these values. To find these values run the following command:

find /dev/input -name mouse* | parallel udevadm info --query=path --name={} | parallel udevadm info --query=all --path={} | grep 'VENDOR\|NAME'

Acceleration (but not sensitivity) can also be configured through xset.

Get current values:

xset q | grep -A 1 Pointer

Set values (substitute numbers for placeholders):

xset m NUMERATOR/DENOMINATOR THRESHOLD

Categories:

Linux Configuration