Sudden Motion Sensor And Skipped Frames In New PowerBooks

dude_funk · 02-21-2005, 04:39 PM

Hi All,

Below is a forwarded message originally posted (by Ms. Marianna Montague) on an Avid-users forum. Those running Avid or Final Cut Pro in new Powerbooks may be interested:

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Apple’s last batch of PowerBooks incorporate a technology called “Sudden Motion Sensor”, that is supposed to park the hard drive heads when sensors detect the system is being dropped or jarred. Apple posted a support note that recommends turning off SMS if you see skipped frames. It sounds like under some circumstances, the SMS can kick in and interrupt the drive temporarily. Please refer to Apple's web site on how to turn it off anf for further instructions about this feature but here are the general steps to disable it. Please note turning this feature off means you will not have this feature available to you.

To disable the Sudden Motion Sensor

From the Finder's Go menu, choose Utilities.

In the Utilities folder, open Terminal.

When the command line appears, type pmset -g # and press Return. The default setting is "1" (turned on).

If the above command returns "1," you can disable the Sudden Motion Sensor by typing sudo pmset -a ams 0 and pressing Return (changing the setting to a zero disables the module).

Type your administrator password when you are prompted and press Return.

Type the pmset -g # command again to be sure the setting has been applied.

Any changes that you make to the Sudden Motion Sensor setting remains in effect even after you restart the computer.

To re-enable the Sudden Motion Sensor:

From the Finder's Go menu, choose Utilities.

In the Utilities folder, open Terminal.

When the command line appears, type pmset -g # and press Return. If you have the Sudden Motion Sensor turned off, the command will return a zero (0).

If the above command returns a zero, you can re-enable the Sudden Motion Sensor by typing sudo pmset -a ams 1 and pressing Return.

Type your administrator password when you are prompted and press Return.

Type the pmset -g # command again to be sure the setting has been applied.

**Sponsor** · 02-21-2005 04:39 PM

**daney_waney** · 02-21-2005, 06:33 PM

how do you know if your book has a sudden motion sensor?

**cyberprince** · 02-21-2005, 07:23 PM

Only the Powerbooks that were released last month have Suden Motion Sensors installed. Previous versions do not have SMS. Last time I checked these powerbooks aren't available locally yet.

**imabs** · 10-02-2008, 12:14 AM

good thing i don't have this Sudden Motion Sensor in my PowerBook.

**rafaelc378** · 10-02-2008, 12:23 AM

Wow, talk about raising the dead. This thread's almost 4 years old.

The one time I had to run FCP on my MacBook (with SMS) on a project I was doing, I never had any dropped/skipped frames. But then again, it's a MB, not a PB and it was a newer version of FCP than the one available in early 2005.