Yes, its enabled by default with an Apple SSD.
Find the current status of Sudden Motion Sensor:
- From the Finder's Go menu, choose Utilities.
- In the Utilities folder, open Terminal.
- When the command line appears, type sudo pmset -g and press Return.
- Type in the administrator password when prompted and hit Return. This command queries the computer for the current setting of the Sudden Motion Sensor, which you can determine by locating the ams entry (in Mac OS X 10.3) or the sms entry (in Mac OS X 10.4, 10.5, 10.6, and 10.7) and looking to the right to determine its value. The default setting is "1" (turned on).