ps2rate is a Windows (95, 98 and ME) tool that changes the
refresh rate of the ps/2 mouse. The mouse can be
configured to operate at 10, 20, 40, 60, 80 (usually default),
100 and 200 Hz.
ps2rate uses a VXD to send a set-rate message directly to
the mouse hardware.
See mouse protocol for an explanation of how it is done.
With the advent of Windows 2000 and Windows XP, both based on the windows NT kernel, ps2rate has been obsolated twice : firstly because it doesn't work under these OSes and secondly because the new mouse drivers (at least the default Microsoft PS/2 driver) implement this feature.
The mouse refresh rate should be at least equal to the screen refresh
rate
(keep in mind though that you won't see more samples than the video card
actually displays).
Changing the refresh rate is a good idea if you feel that your mouse movement
isn't smooth enough.
Many people object that USB mice's movement is smoother and silkier. This is because the default refresh rate of an USB mouse is higher than a PS/2 or serial mouse. On Solaris systems it can be as low as 40 Hz by default !
This tool is mainly used by quakers who tune their system to get the
higher FPS possible and need the softest mouse movement
possible to frag their enemies.