If you're wondering what Google Earth experts do to make things run faster or better, then read this article. This blog entry describes tips on how to set up your Google Earth 5 options ("Preferences" on the Mac). These options can greatly improve your experience with Google Earth by optimizing important graphics and data constraints, speeding up certain actions, or improving the quality of your views.
To get to the GE options, select the menu "Tools -> Options" (or "Google Earth -> Preferences" on the Mac). This opens a window of options with the following panes: 3D View,Cache, Touring, Navigation, General. [...]
Read more: http://www.gearthblog.com/blog/archives/2009/03/setting_up_google_earth_options.html