In 2005 and 2006, Apple switched the CPUs of Mac and Xserve computers from PowerPC to the x86 architecture from Intel.
The change was announced at the 2005 Worldwide Developers Conference (WWDC) by then-Apple CEO Steve Jobs, who said Apple would gradually stop using PowerPC microprocessors supplied by Freescale (formerly Motorola) and IBM.
This was the second time Apple changed the processor instruction set architecture of its personal computers. The first was in 1994, when Apple discarded the Mac's original Motorola 68000 series architecture in favor of the then-new PowerPC platform.
Apple's initial press release said the move would begin by June 2006 and finish by early 2008, but it actually proceeded much more quickly. The first-generation Intel-based Macintoshes were released in January 2006 with Mac OS X 10.4.4 Tiger. In August, Jobs announced the last models to switch, with the Mac Pro available immediately and the Intel Xserve available by October (it actually shipped in December).
The final version of Apple's Mac OS X that ran on PowerPC chips was 2007's Leopard (version 10.5), released in October 2007. The final version to run applications written for PowerPC chips, using the Rosetta binary translator, was 2009's Snow Leopard (version 10.6). Mac OS X Lion (version 10.7) dropped support altogether.
In 2020, Apple announced that it would shift its Mac line to Apple silicon, which are ARM-based processors developed in-house.
Background
Apple had been using PowerPC processors in its products for 11 years when the move to Intel processors was announced.
At 2003's WWDC keynote address, Jobs unveiled a Power Mac with a processor from IBM's PowerPC G5 product line, the first personal computer to feature a 64-bit processor.
He promised a 3 GHz Power Mac G5 within 12 months, but never released such a product. In 2004's WWDC keynote address, Jobs addressed the broken promise, saying IBM had trouble moving to a fabrication process lower than the 90 nm process. Apple officials also said in 2003 they planned to release a PowerBook with a G5 processor, but such a product never materialized. Tim Cook, then Apple's Executive Vice President of Worldwide Sales and Operations, said during an earnings call that putting a G5 in a PowerBook was "the mother of all thermal challenges".
In addition, there were reports that IBM officials had concerns over the profitability of a low-volume business, which caused tensions with Apple and its desires for a wide variety of PowerPC processors.
History
1980s
Apple's efforts to move to Intel hardware began in 1985. A proposal was floated after Jobs departed but was quickly disapproved by management.
1990s
The first known attempt by Apple to move to Intel's platform was the Star Trek project, a code name given to a secret project to run a port of Classic Mac OS System 7 and its applications on an Intel-compatible personal computer. The effort began on February 14, 1992, with the blessing of Intel's then-CEO Andy Grove.
Apple leaders set an October 31 deadline to create a working prototype. The team met that deadline, and had a functional demo ready by December. John Sculley's departure during the Star Trek project was a factor in the project's termination. Michael Spindler, who took over as Apple's CEO, devoted most of Apple's resources to moving to PowerPC instead, thus initiating Apple's first processor transition.
After Apple's 1997 acquisition of NeXT, Apple began to rework their NeXTSTEP operating system into a successor to the classic Mac OS, codenamed Rhapsody. Jobs (who rejoined Apple upon the purchase) demonstrated an Intel-compatible build of Rhapsody to Dell founder and namesake Michael Dell. Jobs offered to license the new OS to Dell for its PCs, so that users could choose between it and Windows. However, Dell declined when Jobs insisted that the company license the operating system for every PC it ships, regardless of whether or not the user wanted to use Mac OS.
Early 2000s
In the years since the end of the Star Trek project, there were reports of Apple working to port its operating system to Intel's x86 processors, with one engineer managing to get Apple's OS to run on a number of Intel-powered computers.
In 2001, Jobs and then Sony president Kunitake Andō reportedly had a meeting to discuss the possibility of running Apple's operating system on its Vaio computers. Jobs even presented a Vaio running Mac OS. Such negotiations ultimately came to nothing.