Download of 27-inch iMac EFI FW Update 1.0 for Mac was available from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. We recommend checking the downloaded files with any free antivirus. This free Mac app was originally created by Apple Inc. 27-inch iMac EFI FW Update for Mac lies within System Tools, more precisely System Optimization.
From the developer:
27-inch iMac EFI FW Update is recommended for all quad-core Intel Core i5 and Core i7 processors 27-inch iMacs. The app solves an issue that sometimes caused high processor utilization while playing audio through the headphone output mini-jack. In addition, it solves an issue that prevented the display backlight from turning on after powering on the iMac.
You may want to check out more software for Mac, such as MacBook EFI Firmware Update, which might be related to 27-inch iMac EFI FW Update.
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