Lucky me, I found this post: http://forums.linuxmint.com/viewtopic.php?f=49&t=109267
and this wiki: https://wiki.archlinux.org/index.php/Mouse_Polling_Rate
I only had to edit /etc/modules file, adding these two lines:
-r usbhidSave and reboot!
It is '2' (ms) in my case because I wanted to set it to 500Hz. Other common values are:
As you can see, the higher is the frequency at which the usb port communicates, the lower is the response time (orly?).
Hope it helps you :)