What’s an accelerometer sensor doing inside the M2 MacBook Air?

Apple stopped using a sudden motion sensor in its Intel-based laptops years ago. But surprisingly enough, the new M2 MacBook Air rocks an accelerometer sensor.

The M2 MacBook Air logic board with an accelerometer sensor highlighted in red
The accelerometer sensor in the M2 MacBook Air, highlighted in red | Image: iFixit

An accelerometer is lurking in the M2 MacBook Air

A teardown analysis of the new M2 MacBook Air, performed by repair site iFixit, has determined that there’s an accelerometer sensor inside this computer. It’s been identified as the Sensortec 6-axis MEMS accelerometer and gyroscope, supplied by Bosch. This is your typical accelerometer for movement detection, not too dissimilar from one in your iPhone. And it’s a surprise because Apple stopped using accelerometers in its notebooks quite a few years ago. Read: 50 cool iPhone tips

In old notebooks, the sensor protected the hard drive in an unfortunate case you accidentally dropped your machine. Apple hasn’t commented on the matter and iFixit couldn’t tell what’s an accelerometer doing inside the new Air either. Our best guess would be that the new Air and any future Apple silicon laptops will use this sensor to detect… sudden falls. In turn, this could inform Apple’s support whether you have accidentally dropped the laptop when you bring it for service.

As a side-note, an accelerometer is widely used for motion controls in tilt-based games, but we don’t think that makes much sense on a computer.

Protecting against accidental damage with AppleCare

Apple’s standard 1-year warranty does not cover accidental damage from accidental falls but upgrading to an optional AppleCare coverage does. AppleCare for the M2 MacBook Air is $80 per year or $229 if you pay upfront for three years of extended protection. An additional service fee of $99 applies in case of other accidental damage (excluding damage to the display or cosmetic damage on the enclosure).

This is to say that you’ll be paying at least $229 (your three years of AppleCare) and an additional $99 (a service fee) should you drop and damage your brand spanking new M2 MacBook Air. So $328 with Apple Care (if you don’t have one, good luck to you). And thanks to that accelerometer sensor, Apple will be able to tell whether you have really damaged the laptop by accidentally dropping it or not.

How does Apple’s sudden motion sensor technology work?

Hard drives are mechanical storage devices with fixed rotating platters, coated with magnetic material to read and write data on it . All Intel-based Apple laptops with hard drives took advantage of sudden motion technology to guard the spinning platters. Sudden motion technology is just a fancy name for an accelerometer sensor capable of sensing fine movement across all three axes. So if a Mac equipped with a hard drive took a fall, the sensor would pick up a motion suggestive of a sudden fall. In response, your Mac would rapidly park the magnetic heads, arranged on a moving actuator arm, to protect the drive from damage and data loss.

Here’s how Apple describes the sudden motion sensor:

Th sudden motion sensor is designed to detect unusually strong vibrations, sudden changes in position and accelerated movement. If the sensor detects any of these, it instantly parks the hard drive heads to help reduce the risk of damage to the hard drive in case of impact. When the sensor detects that the computer’s position is once again stable, it unlocks the hard drive heads and returns to normal operation.

But Apple hasn’t been selling laptops with hard drives for years now. The MacBook Air and other Apple laptops are all equipped with solid-state storage (SSD) which is much faster because there are no moving parts. “Computers with solid state drives or flash storage do not use the sudden motion sensor as the drives have no moving parts,” Apple’s support document acknowledges. Those interested can peruse the document for step-by-step instructions explaining how to determine whether your computer has a sudden motion sensor and how to manually turn it off.

Curiously, the Studio Display also has an accelerometer sensor.