Cycle preferences are only available when Advanced Editing is selected in Advanced preferences.
Cycle Pre-Processing pop-up menu: Processes a cycle jump slightly before its actual position, in order to ensure a smooth cycle jump from the end point to the start point of the cycle. You can change the pre-processing time. The default value of Off should be suitable for most uses.
Smooth Cycle Algorithm checkbox: Improves the timing of cycle jumps, making it easier to set the length of sample loops while in Cycle mode. If your computer has a very slow processor, this setting reduces the processing requirements for graphics operations. If you’re working in a style that involves frequent cycling of musical sections, you’ll want to select this checkbox. If you find that your cycled sections aren’t as smooth as you’d like (assuming that your loops are actually perfect), the default value of Off should achieve better results. The use of Apple Loops somewhat mitigates the need for this setting.