The Pane Mobile Settings

The pane Mobile Settings is only visible if you are using TinkerTool System on a mobile computer. The settings controlled by it are not available on desktop computers.

Motion Sensor

Mobile Apple computers usually contain a hardware feature known as Sudden Motion Sensor. This sensor measures the current acceleration of the computer and lets the system automatically protect the hard disk against destruction if a free fall of the computer is detected. The read/write heads will be moved into a safe parking position, so the drive won't be destroyed even if the computer drops onto the ground. Under very particular circumstances however, it might be helpful to deactivate the sensor. When your computer is put into an environment with strong vibrations, the sensor could mistakenly think the system is falling, parking and unparking the hard disks over and over again, causing a significant performance drop. For this case you can deactivate the motion sensor. To change the setting, perform the following steps:

Open the tab item Motion Sensor on the pane Mobile Settings.
Click one of the buttons Enable sensor or Disable sensor.

If your computer is not equipped with a motion sensor, the option won't be selectable. Only Apple's original sensors that are under control of Mac OS X will be affected by this setting, not other sensors inside some third-party hard drive models which are designed to work independently. Mobile Apple computers built in 2005 or later usually contain a sudden motion sensor.

You should never switch off the sensor unless absolutely necessary. Disabling the sensor is only recommended if you experience performance problems in environments with external vibrations, like live concert halls, recording studios, or dance clubs. It also makes sense to deactivate the sensor if you have replaced your hard drive by a third-party model which comes with its own motion sensor. The drive's sensor and Apple's sensor could influence each other, seriously degrading performance of the drive.

Wake Up

If you have a portable computer with a display lid, you can put your computer to sleep mode by closing the lid. Mac OS X will automatically wake up the system when the lid is being reopened later. Under some circumstances, this automatic wake-up may not be desired. You can prevent Mac OS X from doing so by changing a system setting. Perform the following steps:

Open the tab item Wake Up on the pane Mobile Settings.
Click the button Don't wake automatically.

You can return to the normal setting Wake when lid is being opened any time.

Safe Sleep

When a computer enters sleep mode to save energy, most hardware parts will be shut down, but the main memory and the parts needed to wake up the computer still remain powered. Keeping the main memory in operation is necessary to maintain the current state of the computer. When waking up, the computer can just resume operations based on the still intact contents of its memory.

Problems will occur if the computer loses power during sleep mode: The contents of the main memory will be lost, and the computer cannot resume operations. Furthermore, the operating system has not been shut down properly. This is the same situation as losing power outside sleep mode. The operating system will have to be rebooted and it must perform recovery steps on all hard drives to return to a clean state.

For mobile computers, such situations are not uncommon, however, because the battery could be drained completely when the sleep period is very long. The user may also have attempted to replace the battery during sleep mode, not recognizing that the computer was actually on but sleeping. A solution of this problem is possible if the computer is saving the whole contents of memory to a reserved area on its hard disk just before it enters sleep mode. In this case, the data on the disk can be used as a backup should the computer indeed lose the contents of its memory during sleep mode. This way it can still restore its full internal state and just resume operations. When waking after a power failure, the computer just has to copy the contents from the reserved disk area back into main memory again.

Apple calls this protection feature Safe Sleep. Other vendors usually call it Hibernation Mode. At the technical level, this feature is called Suspend-to-Disk or ACPI state S4.

Not all computers are capable of supporting Safe Sleep. It requires special features in the hardware, in the firmware, and in the operating system. If an Apple system makes active use of Safe Sleep recovery during wake-up, you will recognize this by a gray progress bar which is laid over the normal screen image.

Safe Sleep is a useful feature, but it can also have disadvantages:

The operating system has to reserve a large area on the computer's internal hard disk to hold the backup copy of main memory during sleep mode. This is called the Safe Sleep file and it will always have the same size as the physical RAM size of your computer.
When entering sleep mode, the contents of the RAM must be written to the Safe Sleep file, which will delay the begin of the actual sleep mode by a few seconds. Simply speaking, it will take a bit longer to bring the computer to sleep mode. In the time between full operation and actual entry of sleep mode, the main hard disk is in active use, but it won't be protected by the sudden motion sensor during this period because the operating system will have entered an inactive state already.

TinkerTool System can enable or disable Safe Sleep mode, under the prerequisite that your combination of computer model, firmware and OS version allows the use of Safe Sleep in general. Perform the following steps:

Open the tab item Safe Sleep on the pane Mobile Settings.
Click on the button Enable Safe Sleep or Disable Safe Sleep.

The current size of the sleep file will be shown. If Safe Sleep is shut off, the file can be removed by pressing the button Delete file now. The reserved area on the hard drive will be returned to normal usage.