by Tom Nelson
The SMC (System Management Controller) controls a number of the Mac’s core functions. The SMC is a chunk of hardware incorporated into the Mac’s motherboard. Its purpose is to free the Mac’s processor from having to actively take care of rudimentary hardware functions.
Spencer Platt/Getty Images News
What the SMC Controls
Depending on your Mac model, the SMC performs the following functions:
- Responds to the press of the power button, including deciding whether the press is for a power off, sleep, or an accidental misstep by your cat.
- Detects and responds to the opening or closing of the lid of a portable Mac.
- Manages a portable’s battery performance, including charging, calibration, and displaying remaining battery time.
- Thermal management of your Mac’s interior. This is primarily accomplished by sensing temperature at various places inside your Mac, and then adjusting fan speed to create or reduce airflow.