What it does
Restricts shaking to times when CPU usage exceeds the threshold you set. With sustained-CPU enabled, the condition only passes if the CPU has been over the threshold for the chosen window.
How it works
Shake It On samples CPU via mach `host_statistics` on every tick. The instantaneous check uses the most recent reading. The sustained-CPU mode averages samples in a ring buffer over your chosen window before deciding.
Where to find it
Settings → Only Shake If → CPU is above threshold. Reveals a 10–100% threshold slider plus the 'For at least' segmented picker.
When to use it
Sustained-CPU is the right answer for renders, encodes, and ML workloads — anything that has spiky CPU but should keep the Mac awake for the whole session.
Tips
- Pair with 'Allow display to sleep' so the Mac stays running but the screen dims overnight.
- Set the sustained window to 1 minute for renders; 10 seconds is enough for short builds.