How to Reset PRAM on a MacBook Pro or Air

When the Mac goes haywire, good advice is often expensive. But before you start dismantling your workstation and dragging it to the Apple store, you should first take a look at the so-called PRAM (Parameter Random Access Memory) or NVRAM (Non-Volatile Random Access Memory): This normally runs dutifully in the background and is responsible for system functions below the operating system. However, crashes or shutdown errors can throw it out of sync, which can cause a variety of strange behaviors on the Mac.

  • What is the PRAM for?
  • PRAM reset: This is how it works

What is the PRAM for?

The PRAM or NVRAM stores configuration snippets that are useful before the operating system actually starts. If an error occurs here, it may lead to strange behavior of the Mac system. Among other things, the Mac stores the following values in this memory:

  • Startup drive
  • Mouse speed
  • Speaker volume
  • Keyboard and mouse information
  • Screen resolution
  • and many small basic settings more.

A PRAM reset is always useful if the Mac is behaving "strangely", such as showing weird screen resolutions, crashing regularly when performing certain actions, or taking seemingly forever to boot. After the reset, the default values are set: So test if everything works as it should again. Otherwise, you should try an SMC reset

PRAM reset: This is how it works

You don’t need much prior knowledge to perform a PRAM reset on your Mac: Apple has designed the system in such a way that a reset is child’s play:

  • Shut down the Mac.
  • Turn the Mac back on.
  • Immediately after turning it on, hold down the key combination [cmd] + [option] + [P] + [R] until the Mac restarts again.
  • On older models, the startup chime will be heard a second time. On newer models this is missing, instead you will see the apple a second time.
  • You can now release the keys: PRAM is reset and the Mac boots normally.