Techniques and tools for reducing power consumption of computing devices (e.g., mobile devices such as mobile phones and tablet computers) that perform position tracking operations are described. In described examples, a low-power processor calculates (e.g., in real time) position information (e.g., GPS position fixes) based on information received from a positioning system (e.g., GPS) and stores the position information for later use in a buffer associated with the low-power processor (e.g., in storage on the low-power processor). Described examples allow position information to be calculated in real time and stored while the device is in a low-power state, and can be used with location-based applications that do not require position information to be delivered to the application in real time.