Following the release of firmware updates for the 2011 MacBook Pro, MacBook Air and Mac mini, Apple has also released an EFI update for the 2011 iMac, finally bringing Lion Internet Recovery to the latest generation of iMacs, as well as patching Thunderbolt performance issues.
Originally launched in July alongside OS X Lion and updated Mac Minis and MacBook Airs, Lion Internet Restore lets users restore their computers over the internet onto a blank hard drive, making it easier to install a new drive with a fresh install of Lion or recover from hard drive failure. The feature was later added to the early 2011 MacBook Pro last month.
Now that Apple has released an update to bring this function to the 2011 iMac, every current Mac model that Apple sells (except for the Mac Pro) are now able to use Internet Recovery. The update is available now through Software Update, or for direct download (link).
iMac EFI Update 1.7
This update enables Lion Recovery from an Internet connection and includes fixes that resolve issues with Apple Thunderbolt Display compatibility and Thunderbolt Target Disk Mode performance on iMac (early 2011) models.
For more information about Lion Recovery, please visit http://www.apple.com/macosx/recovery/.
The iMac EFI Update will update the EFI firmware on your iMac computer. When your iMac restarts, a gray screen will appear with a status bar to indicate the progress of the update. It will take several minutes for the update to complete. Do not disturb or shut off the power on your iMac during this update.
Boot ROM or SMC Version Information: After iMac EFIupdate has successfully completed, your Boot ROM Version will be IM121.88Z.0047.B1D.1110171110