Yesterday we touched on bluetooth problems that people were experiencing with Apple's new Magic Mouse, which have sounded more like problems with the bluetooth reception than anything to do with the mouse. There is another Magic Mouse problem some people are having, which is slow tracking movement that seems to be inherent in the new devices.
Apple discussion poster "Evan Kohn" writes:
"I just got the new mouse. I have the tracking speed turned up to the highest level, but it seems like I still need to move the mouse a larger distance than my previous mouse to cover the same distance on the screen."
This slow tracking seems to happen regardless of whether or not those affected have updated their system software or installed the Magic Mouse update which Apple released a little while ago.
It seems some acceleration or scaling factor for mouse movement is not properly set for a number of systems, which is resulting in this behavior. One possibility could be that the mouse acceleration scaling is turned off or is at such a low setting that the mouse response is linear. As such, you can try changing the mouse scaling factor to better suit your needs. Running the following command in the terminal will change the scaling factor:
defaults write -g com.apple.mouse.scaling NUMBER
Run this command several times with different values for NUMBER (use 2 as a starting point, and go up or down by 0.1 to get in the right ballpark) to find the value that works best for you. For each value, try changing the mouse's tracking speed in the system preferences to see what combination works best.
This can also be done with the "Mouse Zoom" utility, which is built to speed up the mouse cursor movement in OS X. It has not been updated in a few years, but according to some people it has worked for their slow Magic Mice.
Being a new device with unique inputs, the Magic Mouse currently is only supported by the official drivers; however, third-party input managers such as USB Overdrive are being updated to work with the new mice. On the USB Overdrive website, developer Alessandro Montalcini mentions he is currently in the process of implementing code to do a lot more than the basic gestures that Apple supports in their drivers. I am looking forward to seeing what is possible with the new mice.