Long story short: To scroll start slow, to swipe act fast.
How scrolling works
If you touch the Magic Trackpad surface with two fingers and move them slowly an accumulated threshold distance over time, our driver switches to scroll-mode. Now scroll as fast as you like, scroll-mode stays active as long as you lift all fingers.
- Adjust that threshold distance with the Sense slider to avoid accidental scrolling.
How swiping works
To swipe you need to lift all fingers. Now touch the surface and move your finger(s) fast and lift them again. A swipe is triggered only if the distance between touch reports was far enough. Actually you need to flick your finger(s).
It may happen that you like to scroll but start to fast and trigger a swipe instead.
- Adjust that swipe trigger distance with the Sense slider to make swiping easier or to avoid accidental scrolling.
The slightest touch of any finger, or even just hovering 1 millimeter above the trackpad surface, will create a constant stream of touch data transmitted either wirelessly via Bluetooth or the USB cable to the computer.
There are 90 touch reports per second for a maximum of 11 fingers, which is about 9.5 kByte or 76 kBit per second. That was fast internet modem speed back in the 90's.
This data is processed by our driver and translated into mouse scroll events to emulate real scroll wheel(s)..
If you always rest your finger(s) on the surface, you drain the battery much quicker in case you are connected via Bluetooth. To save battery, lift all fingers if you don't need them.