If you have a ScrollPane with a large amount of content then each click(notch) on the scroll wheel on the mouse is many screens worth of content. It is much worse on Windows than Mac but is bad on both. If you look at the attached test case which just has 100,000 lines of text in a single Text node as child of ScrollPane. On Windows one click of mouse wheel is more than 10,000 lines scrolled. On Mac it is only 250 lines but as only 25 lines fit in the window that is still 10 screens worth.