Learn how to manage and optimize the Sudden Motion Sensor (SMS) on your Mac for enhanced data protection and a better user experience.
The Sudden Motion Sensor (SMS) is a feature built into Apple laptops that detects sudden movements or changes in the orientation of your Mac. It plays a crucial role in protecting your hard drive from potential damage caused by sudden drops or impacts. When the SMS senses a sudden motion, it instantly parks the hard drive heads, preventing them from damaging the delicate internal components.
To provide information about managing the Sudden Motion Sensor (SMS) on your Mac in a tabular format, I’ll create a table with clear headings and concise instructions. This table will include steps for accessing system preferences, finding the relevant settings, and adjusting the SMS to your needs. Keep in mind that the specific steps may vary slightly depending on the version of macOS you are using.
| Step | Action | Description |
|---|---|---|
| 1. | Access System Preferences | Click on the Apple menu () at the top left of your screen and select “System Preferences.” |
| 2. | Open Energy Saver | In the System Preferences window, click on “Energy Saver” (or “Battery” for newer macOS versions). |
| 3. | Find SMS Settings | Look for a checkbox or setting related to the Sudden Motion Sensor. This might be labeled differently based on your Mac model and macOS version. |
| 4. | Adjust SMS Settings | If available, adjust the SMS settings according to your preference. You might be able to turn it on or off, or adjust its sensitivity. |
| 5. | Save Changes | Ensure that you save any changes you make to the settings. |
| 6. | Close Preferences | Close the System Preferences window. |
Note: Some newer Mac models, especially those with solid-state drives (SSDs), may not have an adjustable Sudden Motion Sensor, as SSDs are not susceptible to damage from sudden movements like traditional hard drives.
Check the status of SMS on your Mac
Apple does not provide an application specifically designed to monitor the sudden movement of sensors, but OS X includes the increasingly convenient Terminal application , which we previously used for the interior of our Mac.
- Start the terminal located in / Applications / Utilities /.
- When prompted for the command line, enter the following (you can copy / paste the text instead of entering it if you prefer):
- sudo pmset -g
- Press the key to enter or return the keyboard.
- You will be asked for your administrator password; enter the password and press enter or return.
- The terminal will display the current settings of the power management system (“pm” in memory), which includes the SMS settings. A lot of elements will be listed. Find the SMS item and compare the value with the list below to understand its meaning:
- sms – 0: The sudden motion sensor is deactivated.
- sms – 1: The sensor is on.
- No sms entries: Your Mac is not equipped with an SMS system.
Activate the SMS system on your Mac
If you’re using a Mac that comes with a hard drive, it’s a good idea to turn on the SMS system. A few exceptions are noted above, but overall, if your Mac has a hard drive, you’re better off with the system enabled.
- Start the terminal.
- At the command prompt, type the following (you can copy / paste):
- sudo pmset -a sms 1
- Press enter or return.
- If you are asked for your administrator password, enter the password and press enter or return.
- The SMS system activation command does not give any feedback on whether it is successful or not; you will just see the explanation of the terminal prompt. If you want to make sure the command is accepted, you can use the “Check SMS status on your Mac” method described above.
Disable the SMS system on your Mac
We’ve already mentioned a few reasons why you might want to disable the sudden motion system on the Mac’s motion sensor. We will add another one to this list of reasons. If your Mac is only equipped with an SSD , there is no advantage in trying to park the device heads, as there are no SSDs; in fact, there are no moving parts.
The SMS system is mostly a hindrance for Macs that only have an SSD installed. This is because in addition to trying to park non-existent SSD heads, your Mac will also stop any SSD writing or reading while the SMS system detects movement. Since the SSD has no moving parts, there is no reason to turn it off due to low movement or a little stuttering while the SMS waits for your Mac to return to stable condition.
- Start the terminal.
- At the command prompt, type the following (you can copy / paste):
- sudo pmset -a sms 0
- Press enter or return.
- If you are asked for your administrator password, enter the password and press enter or return.
- If you want to make sure SMS is turned off, use the procedure described above in “Checking the SMS Status of Your Mac.”
The Sudden Motion Sensor (SMS) is a valuable feature that ensures the safety of your Mac’s hard drive. By understanding and managing the SMS settings on your Mac, you can proactively protect your data and reduce the risk of drive damage. Follow the steps outlined in this article to effectively manage and optimize the Sudden Motion Sensor on your Mac, resulting in a better user experience and enhanced data protection.
