Audio Developer Conference

Utilizing multiple cores for real-time audio processing is tricky. DSP work needs to be partitioned and distributed to threads, all the while minding real-time constraints: no locks, heap allocations, or unsafe system calls. Things get even trickier on Apple’s mobile devices, which are aggressively tuned to save energy and prolong battery life. As we'll see, even getting optimal single-threaded performance can be a challenge.

First we'll look at the high-level architecture of Apple's mobile processors and the challenges involved in striking a balance between energy usage and performance in the OS. Then we'll examine the frequency scaling and core switching behavior of Apple devices with the help of measurements. Finally, we'll explore ways of mitigating the impact of these power-saving measures on real-time workloads, both for single- and multi-threaded applications.