EFI and SMC firmware updates for Intel-based Macs

This article lists firmware updates that were released for Intel-based Macintosh computers. They update the firmware that originally shipped from the factory. If your computer does not appear on this list, an update from the factory firmware is not necessary. Some firmware updates for Intel-based Macs may not be displayed automatically using Software Update. If they do not appear in Software Update, they must be manually downloaded from the Apple Downloads site. If you are unsure whether your computer needs a particular update, simply download and open the update installer. The installer will alert you if the firmware update is already installed or not needed.