The lowest-level component of RSTask is the speed controller. This component accepts requests to start and stop speed schedules and to transition to idle and maximum speed states. A speed schedule consists of a sequence of phases, each with a speed to use and a duration in multiples of the scheduling granularity. The speed controller internally handles any CPU-specific commands to change the speed. This modularity aided in porting RightSpeed to two different chips with different voltage scaling commands.
The scheduler also exports routines to pause and resume the current schedule when the CPU starts and stops waiting for I/O. A pause changes the speed to the minimum available. A resume determines how long the CPU spent waiting for I/O, accelerates the remaining part of the schedule accordingly, and resumes that schedule.