About EFI firmware updates

Learn how to identify if your Intel-based Macintosh computer needs an EFI firmware update and how to apply EFI firmware updates to Intel-based Macintosh computers.

First, determine that your computer needs an EFI firmware update. Choose Apple () > Software Update to see if an EFI update is available for your computer, or follow these steps:

  1. Find out which version of firmware you have currently by checking System Profiler.  Refer to the section "Checking your computer's EFI Boot ROM or SMC firmware version" of EFI and SMC firmware updates for Intel-based Macs for detailed instructions.
  2. Compare your firmware version with the version listed in this table of current EFI firmware updates.
  3. If your firmware version matches one listed in the table, your computer does not require any additional firmware updates. However, if your firmware version does not match one listed in the table, you should upgrade by continuing with the steps in this article.

Quit all open applications, then download and install the firmware update.

Note: Some USB and FireWire devices may prevent firmware updates from installing correctly; disconnect non-essential devices and use only an Apple keyboard and mouse to apply the update.

  1. Click the appropriate link in the table in EFI and SMC firmware updates for Intel-based Macs to download the right update for your computer.
  2. The downloader will place the disk image with an installer in your downloads folder or the location specified in the General tab under Safari > Preferences. If you downloaded the disk image via Safari, Safari will notify you that an application is in the image. Click OK to continue.
  3. If "Open safe files after downloading" is enabled in Safari preferences, the disk image file will mount by itself. If that preference is not enabled in Safari, double-click the disk image to mount it.
  4. In the mounted disk image, double-click the .pkg file to start the firmware update process.
  5. A Welcome screen will appear.  The onscreen instructions will guide you through the update process.  Click Continue.
  6. An information screen will provide you with more detail on the update. Click Continue.
  7. A Software License Agreement will appear.  Click Continue.  To Agree to its terms, Click Agree.
  8. Select a hard drive to temporarily install the EFI Firmware Update software; the updater application will delete itself after the update is complete.  A green arrow indicates your selection.  Click Continue.
  9. Click Install to proceed with the installation.
  10. You will be asked for your administrator password.  Enter it and click OK.
  11. A dialog box should appear, indicating that a restart is required to complete the installation.  Click Continue Installation.
  12. The Firmware Update software will install. Click Restart to begin the EFI Firmware Update process.
  13. The screen will turn black and may remain black for several seconds.You do not need to touch your computer to start the update.
  14. A long tone will play.  The computer will restart with a gray screen and an Apple logo.  A progress bar at the bottom of the screen will indicate that the EFI firmware update is running.

Important: Do not unplug, shut down, or restart your computer while the update is taking place.

Installation may take several minutes.

  1. After your firmware has been updated, your computer will restart.
  2. If the update to your firmware was interrupted, your computer will attempt to reinstall the update automatically the next time it is powered on. Do not unplug your computer during this process. Your computer will restart by itself when the EFI Firmware installation is complete.
  3. If your computer does not restart, contact support for more information.

Important: The hard disk in an Intel-based Mac must be formatted with the GUID partition scheme to apply a firmware update. Intel-based iMac computers are shipped this way from the factory. If you have reformatted your hard disk, you should check which scheme your hard disk is currently using before applying a firmware update. See Firmware updates for Intel-based Macs require a GUID partition scheme for more information. If you try to apply the update to a hard disk that utilizes any formatting scheme other than the GUID partition, the update will be unsuccessful.

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