Apple Begins the Intel Mac Era

Steve Jobs opened Macworld Expo 2006 on January 10, 2006 at the Moscone Center in San Francisco with the announcement that Apple had shipped its first Intel-based Macs — available for purchase that day: an updated iMac with Intel Core Duo at 1.83 and 2.0 GHz (17-inch at $1,299; 20-inch at $1,699) and the MacBook Pro, a new name replacing the PowerBook G4 line, at 1.67 and 1.83 GHz ($1,999 and $2,499). Jobs had announced the intention to switch from PowerPC to Intel at WWDC on June 6, 2005, setting a two-year transition timeline; the actual transition completed in 14 months. The processors were Intel’s dual-core Core Duo (codename Yonah) built on Intel’s 65nm process — the same platform used in Centrino laptop processors — with a shared 2 MB L2 cache and a 31W TDP, making it suitable for the iMac’s all-in-one thermal design and the thin MacBook Pro chassis. The Core Duo delivered substantially better performance per watt than the PowerPC G5 IBM had supplied for the Power Mac and the PowerPC G4 Freescale had supplied for the PowerBook; the G5’s heat output had prevented Apple from shipping a G5-based laptop, leaving the PowerBook G4 at 1.67 GHz as the maximum while Intel laptops had advanced significantly. Jobs demonstrated the iMac Core Duo running a video transcode “four to five times faster” than the Power Mac G5 iMac it replaced.

The software compatibility challenge was the transition’s central engineering problem. The PowerPC instruction set and the x86 instruction set are fundamentally incompatible — a binary compiled for PowerPC executes instructions that have no corresponding meaning on an x86 processor. Apple’s solution was two-pronged: Rosetta, a dynamic binary translation layer developed by Transitive Technologies (acquired by IBM in 2008), which automatically translated PowerPC instructions into x86 equivalents at runtime with approximately 60–80 percent native performance for typical applications; and Universal Binary, Apple’s fat binary format (built with the lipo tool and Xcode 2.1, also shipped January 2006) that stored both PowerPC and Intel compiled code in a single application bundle, with the OS selecting the appropriate architecture at launch. Developers were encouraged to build Universal Binaries for all new releases; Apple released Universal Binary versions of all its own applications on day one. Major applications including Microsoft Office took several months longer — Microsoft Office 2004 ran under Rosetta while Microsoft Office 2008 (January 2008) shipped as the first Universal Binary version. Adobe Creative Suite CS3, shipping in March 2007, was the first Intel-native version of Photoshop, Illustrator, and InDesign — meaning CS2 users on Intel Macs ran Adobe’s professional tools under Rosetta for over a year, which was functional but noticeably slower for complex operations.

The Mac mini received Intel Core Solo and Core Duo processors on February 28, 2006, and the Mac Pro (replacing the Power Mac G5 tower) shipped August 7, 2006 with dual Intel Xeon 5100 (Woodcrest) processors — completing the full Mac lineup transition in 14 months versus the 24-month schedule Jobs had announced. Boot Camp, a free utility enabling Intel Macs to boot Windows XP natively, entered public beta on April 5, 2006; it allowed users to partition their hard drive, install Windows using standard x86 installation media, and reboot between macOS and Windows. Boot Camp was included in Mac OS X 10.5 Leopard (October 26, 2007) and demonstrated that the Intel transition had made Mac hardware a general-purpose x86 platform. Parallels Desktop for Mac launched in May 2006 as the first commercial virtualization solution for Intel Macs, followed by VMware Fusion in August 2007, enabling Windows to run in a window alongside macOS without rebooting. The Intel transition also brought Macs into mainstream benchmark comparisons with Windows PCs for the first time: hardware review sites could directly compare MacBook Pro performance against ThinkPads and Dell Latitudes using identical workloads, and in many comparisons the MacBook Pro’s build quality, display, and battery life proved competitive or superior — significantly improving Mac’s reputation in enterprise and professional markets that had previously been Windows-only on hardware grounds. The transition set the technical foundation for the second major Apple processor transition: in June 2020, Apple announced the move from Intel to Apple Silicon (ARM-based M-series chips), using the same Universal Binary strategy (renamed Universal 2) and a new version of Rosetta (Rosetta 2) to manage compatibility.