4 Years Later: Looking Back at Apple's Switch to Intel

Cnet's Brooke Crothers has an interesting column looking at Apple's decision to switch from PowerPC to Intel CPU, which was unexpectedly announced four years ago at the Worldwide Developer Conference.

The PowerPC Story

The generally accepted theory is that Apple switched architecture because both of its AIM partners, Motorola and IBM, had been unable to deliver on their promises. PowerPC had begun with great promise, based on IBM's POWER architecture and adapted to use some of Motorola's technology from its 88000 RISC chip. The PowerPC 601, 603, 604, and G3 were jointly designed and produced by both IBM and Motorola, and the designs were tweaked to meet Apple's needs.

The first generation of Power Macs had 60 MHz to 80 MHz CPU speeds, and the fastest Power Mac G3 was the 450 MHz Blue & White of 1999. Over time, the G3 moved forward, with the fastest G3 Mac (the 900 MHz iBook G3) shipping in 2003. IBM eventually shipped a 1.1 GHz G3, which made its way into a CPU upgrade for the Blue & White Power Mac.

The PowerPC architecture diverged in 1999, with Motorola adding a "velocity engine" (known as AltiVec) to the RISC design while IBM continued to focus on speed. Motorola's G4 CPU powered Macs starting with the "Sawtooth" Power Mac G4 of late 1999 through the last generation of G4 PowerBooks, which were introduced in October 2005.

Motorola Drops the Ball

The problem was, Motorola had promised Apple a 500 MHz CPU for the "Sawtooth" Power Mac, and Apple had announced a 500 MHz model based on that promise at the end of August 1999. However, Motorola was unable to deliver the new chip in quantity at that speed, and Apple was forced to backpedal. It wasn't until February 2000 that Apple could finally ship a 500 MHz Power Mac.

With Moto unable to deliver faster CPUs, the summer 2000 revision of the Power Mac G4 was only able to offer improved performance by adding a second CPU and claiming "Two brains are better than one." Problem was, the Classic Mac OS couldn't take advantage of that second CPU - and very few programs could. On the plus side, the dual 500 MHz didn't sell for any more than the single 500 MHz model had.

In January 2001, Apple was finally able to announce Power Macs that broke the 500 MHz level. Two "Digital Audio" 533 MHz models, with one and two CPUs, were available immediately, and two faster models (667 MHz and 733 MHz) shipped the following month. Come July, the G4 reached 867 MHz in the original "Quicksilver" Power Mac, followed by 1 GHz in the "Quicksilver 2002" introduced in January 2002. The fastest G4 Power Macs reached 1.42 GHz and were announced a year later.

On the notebook side, G4 PowerBooks eventually reached 1.67 GHz, and some G4 upgrades for Power Macs reached the 2 GHz mark.

IBM Drops the Ball

In addition to providing the fastest G3 chips used in Macs and upgrades, IBM continued to develop its POWER architecture. Apple was eventually able to convince IBM to produce a next generation PowerPC chip with a velocity engine, and the G5 was designed to perform.

Apple announced the first Power Mac G5 models in June 2003, with CPU speeds ranging from 1.6 GHz to 2.0 GHz. Steve Jobs also announced that Apple would be able to deliver a 3 GHz Power Mac G5 within a year, based on promises from IBM. IBM was unable to deliver on that promise in 2004 - and in 2005.

Twice Apple had been burned by its AIM partners. "Fool me once, shame on you. Fool me twice, shame on me."

The Intel Option

When Apple acquired NeXT in 1996, it obtained an operating system that had been optimized for the Intel x86 architecture. As Apple adapted NeXTstep/OpenStep to its PowerPC architecture, it continued to maintain an x86 version "just in case". Thus Steve Jobs was able to confidently announce in June 2005 that Apple would switch to Intel CPUs - the Intel version of OS X already existed.

A Different View on the Switch

Crothers' unnamed source, a former IBM executive from that era, points to another reason for Apple's switch from PowerPC to Intel. While performance and saving face were factors, economics may have played the biggest role.

PowerPC chips didn't have the same economies of scale as Intel CPUs. At the time, Macs represented perhaps 4-5% of the worldwide PC market. Intel alone was producing over ten times as many CPUs as the PowerPC partners combined output of G4 and G5 chips.

Not only were the CPUs expensive, so was the rest of the hardware for G5 Macs. Where G3 and G4 models ran the CPU at many times bus speed (such as a 1 GHz CPU on a 133 MHz bus) and could thus use commodity RAM, the G5 was optimized for a high speed system bus running at one-third or one-half of CPU speed. Where the fastest G4 Macs used a 167 MHz memory bus, the first generation of G5 Power Macs clocked the memory bus at 800 MHz, 900 MHz, and 1 GHz - this obviously required much more costly RAM.

Apple eventually shipped low-end G5 Macs where memory ran at one-third of CPU speed, but even then it was running at 533 MHz to 700 MHz. So in addition to using expensive IBM CPUs, G5 Macs used expensive memory, and Power Mac prices show this.

• 2003 Power Mac G4, 1.0 GHz dual @ $1,499, 1.42 GHz dual @ $2,699
• 2003 Power Mac G5, 1.6 GHz single @ $1,999, 2.0 GHz dual @ $2,999
• 2004 Power Mac G5, 1.8 GHz single @ $1,999, 2.5 GHz dual @ $2,999
• 2005 Power Mac G5, 2.0 GHz dual @ $1,999, 2.7 GHz dual @ $2,999
• dual-core Power Mac G5, 2.0 GHz dual @ $1,999, 2.5 GHz quad @ $3,299

The switch from G4 to G5 had increased the cost of the entry-level Power Mac by one-third due to more expensive CPUs and memory, along with the hardware design that could keep these hot machines from overheating.

The Intel World

At the same time, the entire Windows world was playing on a level field. Everyone had access to the same Intel (and AMD) CPUs and the same memory, as this had been a commodity market ever since the first IBM clones came to market in the early 1980s.

With Intel's forthcoming dual-core designs, Apple would be able to eliminate the expensive IBM CPUs, the costly memory, and the hot, energy demanding G5 architecture and benefit from commodity chips that ran cooler and used less energy.

While everyone expected that this would make Macs more price competitive, the first generation of Intel-based Macs tended to be about $100 more expensive than the models they replaced - most notably the Mac mini, Apple's most affordable Mac, which went from a $499 entry-level price to $599.

That said, the significant boost in processing power more than offset the difference in price (that's even true of the "road apple" 1.5 GHz Core Solo Mac mini, which benchmarked over 65% faster than the 1.5 GHz G4 Mac mini). Only two Mac Pro models have lower Geekbench scores than the Power Mac G5 Quad - and those were entry-level Mac Pro configurations with much lower price tags.

A Smart Move

Although PowerPC architecture has moved forward since 2005, the primary beneficiaries are gamers* - the PlayStation 3, Xbox 360, and Wii consoles are all based on custom PowerPC chips. The "Broadway" CPU in Wii runs a 729 MHz; the competitors both run 3.2 GHz chips. The Xbox 360 uses a 3-core CPU, and the PlayStation 3's Cell processor includes eight coprocessors (a.k.a. Synergistic Processing Elements or SPEs).

Since Apple's move to Intel, almost the entire personal computing world is now based on x86 architecture, and the biggest benefit to Apple isn't commodity pricing for chips or reduced energy consumption, but the fact that Intel-based Macs can all run Windows as necessary. This has made it vastly easier for Windows users to buy a Mac, use Windows when they need it, and discover the benefits of Mac OS X.

Another plus - we no longer have to argue about how a PowerPC chip compare to an x86 one or make claims about theoretical architectural superiority. We're all on a level playing field now.

Apple has grown by leaps and bounds since making the move to Intel. Net Applications reported Mac OS market share at 3.64% for 2005 (based on Internet traffic) and currently puts it at 9.75% for 2009 - an increase of 167% (this doesn't include 0.66% using the iPhone OS, which would put OS X past the 10% mark). Macintosh unit sales grew from about 5 million in 2005 to about 10 million in 2008.

And thanks to Apple's experience with OS X on PowerPC and Intel platforms, it was able to port OS X to the ARM architecture for the CPUs used in the iPhone and iPod touch. This has allowed Apple to triple its installed OS X user base since the first iPhones shipped two years ago.

Apple doesn't have Microsoft on the ropes, but it has managed to nibble away at Windows market share, which has fallen from over 96% in 2004 to 88% today. Put another way, the share of people on the Internet who are not using Windows has grown from 4% to 12% in five years, with the vast majority (about 80%) of those non-Windows users on OS X.

Apple survived with its unique hardware platform for over 20 years, but it since transitioning to Intel it has reached a broader market than ever before. Migrating to Intel was the right move. It was a smart move. And it has paid off, whatever the true reason for the switch.

* IBM also uses PowerPC in its blade severs.