Disable the Sudden Motion Sensor on a Mac
The Sudden Motion Sensor is designed to protect your Macs hard drive in the event of a computer being dropped or an unusually strong vibration. Essentially what it does is park the hard drive head when movement is detected, which prevents it from potentially scooting across the disk surface and scratching or otherwise damaging the drive or drive head.
Generally speaking, you will want to always have the SMS sensor enabled, but Apple mentions that certain environments are susceptible to unnecessary drive head parking due to the SMS. Basically the SMS detects a strong vibration and then the hard drive parks which can cause video and music playback issues, amongst other annoyances. This is particularly true with concert halls with strong acoustics, recording studios, dance and night clubs, and even walking workstations (the ones with a treadmill under a standing desk). Also, some owners of SSD drives may want to disable the feature.
Disable Sudden Motion Sensor on a Mac Laptop
This works to disable the Sudden Motion Sensor on the MacBook Pro, MacBook Air, MacBook, PowerBook, and iBook running Mac OS X 10.6 and lower:
- Launch Terminal
- Type the following at the command line: sudo pmset -a sms 0
- Hit return and enter your password
The SMS sensor is now disabled, it’s just as easy to reenable again by changing the zero to a one when you need the protection back:
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