Reflecting on the Intel Mac Era’s Highs and Lows as It Nears Its End
The arrival of macOS 27 later this fall won’t completely close the chapter on the Intel Mac. The remaining few models capable of running macOS 26 Tahoe will continue to receive security and Safari updates for an additional two years, and aspects of the Rosetta compatibility layer—designed to enable Intel applications on Apple Silicon Macs—will persist in some form for an uncertain period beyond that.
Still, macOS 26 marks the definitive final chapter of the Intel Mac narrative. Anything that follows is merely a coda or epilogue.
Most of our WWDC coverage has focused on what’s ahead, so allow us a moment to look back at the complete history of the Intel Mac—a collaboration between two companies that made Macs vastly better, until it eventually made them worse.
### “Project Marklar”
The Mac’s relationship with Intel didn’t begin with version 10.4.4, the first Mac OS X release to ship on a commercially available Intel Mac. But we won’t delve into the x86-compatible iterations of NeXTSTEP or Apple’s failed 1990s attempts to create a version of classic Mac OS that could be licensed for third-party x86 systems.
Instead, let’s start with JK Scheinberg, an Apple engineer in June 2000, who was seeking a solo project to ease his transition to working from home. His proposal? A version of the then-unfinished Mac OS X capable of running on Intel processors.
“I’ve been working on the Intel platform for the last week getting continuations working,” Scheinberg wrote to his boss in an email shared by his wife. “I’ve found it interesting and enjoyable, and, if this (an Intel version) is something that could be important to us I’d like to discuss working on it full-time.”
At that point, all Macs still relied on PowerPC processors co-developed by Apple, IBM, and Motorola, as they had since 1994. Early versions of Mac OS X operated on G3 and G4 chips, with the 64-bit G5 processor launching in mid-2003. A version of Mac OS X designed for Intel chips wasn’t essential, and for roughly a year and a half, it existed merely as a hobbyist side endeavor codenamed “Marklar.”
By early 2002, Marklar had gained more attention within Apple, and then-CEO Steve Jobs briefly considered allowing Mac OS X to run on Sony’s Vaio laptops. By that August, around a dozen engineers had joined the project as it evolved from a “proof-of-concept” into a “contingency plan.”
This shift occurred because Apple faced issues with PowerPC chips. Jobs had promised that the desktop G5 would increase in clock speed from 2 GHz to 3 GHz within a year—a promise that never materialized. Additionally, Apple couldn’t fit the hot, power-hungry processor into a laptop; iBooks and PowerBooks remained stuck with revised G4 models. Future CEO Tim Cook described a G5-based laptop as “the mother of all thermal challenges.”
Jobs had been frustrated with PowerPC chips for some time. Walter Isaacson’s biography of Jobs recounts a heated 1997 phone call between Jobs and Motorola CEO Chris Galvin, where Jobs declared that PowerPC chips “sucked.” He may have also harbored other grievances; Geoffrey Cain’s *Steve Jobs in Exile* suggests that Apple’s switch to PowerPC doomed further development of the Motorola m68k chips that NeXT’s computers depended on, contributing to the demise of NeXT’s already-troubled hardware business.
IBM, for its part, was reluctant to devote resources to developing chips exclusively for the low-volume Mac lineup (in 2003, Apple shipped about 3 million Macs; the company no longer reports unit sales in earnings, but analysts estimate that number at just under 26 million Macs in 2025).
Intel’s Paul Otellini helped convince Jobs to make the leap to Intel’s chips, and Apple didn’t have to start the software transition from scratch thanks to its existing work on Marklar. In June 2005, Apple publicly demonstrated Mac OS X 10.4 running on Intel hardware for the first time. Jobs’ presentation obliquely referenced Marklar, though not by name.
“And so today for the first time, I can confirm the rumors that every release of Mac OS X has been compiled for both PowerPC and Intel,” Jobs announced. “This has been going on for the last five years. Just in case.”
### The Transition
The “first” Intel Mac was a Developer Transition Kit (DTK) made available to software developers after WWDC 2005. It was essentially a Pentium 4-based PC housed inside a Power Mac G5 case, available strictly as a loan to developers who paid $499 per year for a developer account and an additional $999 for the kit. Few, if any, of these DTK kits survived; Apple required developers to return them by the end of 2006 and offered to trade them for a real retail Intel Mac to seal the deal.
The WWDC keynote outlined the timeline, as well as the tools Apple would use to help developers and users navigate the transition. The next version of Mac OS X, version 10.5 Leopard, would be compatible with both PowerPC and Intel Macs. A compatibility layer called Rosetta would run most PowerPC apps adequately while developers worked on Intel-native versions, which could be distributed as universal binaries supporting both CPU architectures. This transition worked so smoothly that Apple essentially replicated the same approach for the Intel-to-Apple-Silicon switch.
Apple also capitalized on the fact that its computers would use the same hardware as other PCs. From the start, Apple officially supported running Windows directly on Intel Macs via Boot Camp; a Mac OS X app handled partitioning the Mac’s disk and downloading Windows drivers for the specific Mac, while a Windows-side app supported rebooting back into Mac OS (and eventually offered other conveniences like read-only access to HFS+ formatted volumes).
By January 2006, Apple began shipping the first Intel Macs, starting with a new iMac and a renamed MacBook Pro to replace the outgoing PowerBook series. These initial systems were externally nearly identical to the PowerPC models they replaced—another strategy Apple recycled for the first Apple Silicon Macs, implying that “maybe these machines were different on the inside, but they’re still the Macs you know and love.”
The first new design of the Intel Mac era arrived later that year, when Apple launched the MacBook to replace the old iBook. Like the iBook, this laptop was primarily made of white plastic (a black version, inexplicably several hundred dollars more expensive, was also eventually available), and it used slower processors with Intel’s integrated graphics rather than the MacBook Pro’s dedicated graphics chips. But it was a popular machine—I was a college student at the time, and it was definitely the laptop you’d see most often on campus (or maybe the second-most-often, if you added up every permutation of “something cheap from Dell”).
During the WWDC 2005 presentation, Jobs predicted that the Intel transition would be mostly complete by the end of 2007. Unlike the 3GHz G5 prediction, this one wasn’t optimistic enough: Apple finished its shift from PowerPC to Intel chips with the announcement of a new Mac Pro and Intel-based Xserve in August 2006.
### A Productive Partnership
“As we look ahead, we can envision some amazing products we want to build for you, and we don’t know how to build them with the future PowerPC roadmap,” Jobs said while explaining the rationale for the switch. (It’s amusing to think now, but some of the Mac’s most devoted loyalists reacted to the switch with disproportionate dismay.)
For the first few years of the Intel era, updates came frequently and rapidly. The first wave of Intel Macs briefly reverted to 32-bit chips, a step back from the 64-bit architecture of the G5; this was corrected the following year with a switch to 64-bit Intel Core 2 Duo processors. A flashy new aluminum-and-glass iMac overhaul arrived in 2007, defining an aesthetic still recognizable in today’s Apple products. By the early 2010s, Intel’s rapidly improving integrated GPUs enabled the Mac’s first high-resolution “Retina” displays.
But the most rewarding fruit of the early Apple-Intel partnership—a machine that wouldn’t have been possible with PowerPC chips—was the MacBook Air. For that first model, Intel even created a special version of its Core 2 Duo CPU with 60 percent smaller packaging, something that helped Apple cram an entire laptop into something that could fit in a manila envelope.
That first Air was a bit too ahead of its time; its 4,200 RPM spinning hard drive, in particular, bogged it down, and the features it lacked felt like greater compromises in 2008 than they would have just a few years later. But fast solid-state storage soon became a standard feature, and within just a few years, the MacBook Air became the template for virtually all laptops. This was something Intel both enabled and encouraged.
### Signs of Trouble
Apple began producing its own Apple-branded processors in 2010, using technology it acquired when it bought P.A. Semi in 2008. But while early chips like the Apple A4 and A5 were energy-efficient and felt snappy in iPhones and iPads, it was extremely difficult to imagine their performance scaling up to what Apple would need to replace the Intel chips in a MacBook, let alone an iMac or a Mac Pro.
But these chips steadily improved, year after year, often by huge leaps and bounds. And trouble was brewing at Intel.
By the mid-2010s, Intel’s “Tick-Tock” model for improving its products was starting to falter. The company had more difficulty than expected getting its 14 nm manufacturing process up and running, and its manufacturing improvements stalled for years. Intel’s next-generation 10 nm process didn’t ship in any volume until late 2019, and for years, it was stuck shipping warmed-over iterations of 2015’s 14 nm Skylake architecture.
And it wasn’t just the slowed rate of improvement that was a problem. Former Intel engineer François Piednoël claimed that the Skylake architecture was excessively buggy and that Apple was the one finding many of the bugs.
“Basically our buddies at Apple became the number one filer of problems in the architecture. And that went really, really bad,” said Piednoël. “When your customer starts finding almost as much bugs as you found yourself, you’re not leading into the right place.”
The PowerPC-to-Intel switch happened because Apple was dissatisfied with its current chips and because a better, more viable option was readily available. By the late 2010s, both of those conditions were true again.
### Bridge Over Troubled Water
In retrospect, the first “Apple Silicon Mac” wasn’t the M1 MacBook Air or Mac mini that came out in late 2020 but the redesigned butterfly-keyboard MacBook Pros released in late 2016.
Those models shipped with a now-abandoned technology called the Touch Bar, a narrow strip of touchscreen above the keyboard that attempted to replace the function row with dynamic buttons and sliders that could change based on what the user was doing.
To make the Touch Bar work, those Macs included a chip called the Apple T1. The T1 wasn’t much—it was essentially a repurposed Apple Watch processor that drove the Touch Bar display and provided Macs with a Secure Enclave for Touch ID and Apple Pay. But it was a sign that Intel’s chips were no longer meeting all of Apple’s needs. As in the PowerPC days, Apple was envisioning products that its chip supplier couldn’t help it build.
The T1 was followed by the T2, a relative of the Apple A10 chip that handled the same tasks as the T1 plus additional security features, an SSD controller, and video encoding and decoding. Both the T1 and T2 ran their own operating system called “bridgeOS”—in one sense, the “bridge” referred to communication between those Macs’ Intel processors and the Apple coprocessors. But in retrospect, you could also see it as a reference to those Macs’ role as a bridge between the peak of the Intel Mac era and the impending Apple Silicon era.
### Apple Inside
“When we make bold changes, it’s for one simple yet powerful reason,” said Apple CEO Tim Cook. “So we can make much better products. When we look ahead, we envision some amazing new products, and transitioning to our own custom silicon is what will enable us to bring them to life.”
Cook formally announced the long-rumored Apple Silicon transition during the company’s 2020 WWDC keynote, which was delivered fully virtually at the height of the COVID-19 pandemic. (There’s something faintly odd about watching this video now, even though virtually all of Apple’s major announcements are pre-recorded these days—it’s full of awkward cuts, and it feels like none of the presenters are sure what to do with their hands.)
The first Apple Silicon Macs and the Apple M1 chip were announced in November of that year, and from then on, Intel Macs were living on borrowed time. The Apple Silicon transition took considerably longer than the PowerPC-to-Intel switch had, but the company finally completed the transition in mid-2023.
Apple promised that Intel Macs would be supported for “years to come,” and it did keep that promise, though later Intel Macs received fewer operating system updates than earlier ones. From 2020’s macOS 11 Big Sur to last year’s macOS 26 Tahoe, Apple released a total of six macOS versions that supported both architectures, though Tahoe’s support list included only a handful of Intel models. Those Macs will receive security and Safari updates until the fall of 2028. And then the Intel Mac era will be fully in the rearview.
What’s striking about the Intel Mac era is that Apple switched to and away from Intel chips for essentially the same reason: It was seeking a more compelling processor roadmap and the best possible performance-per-Watt for its chips. When Intel was executing well—and during the decade between the mid-00s and mid-2010s, Intel was executing exceptionally well—Apple wanted in. It was only after years of watching Intel struggle that Apple wanted out.
The big difference? When Apple stopped shipping PowerPC chips, consumer-focused PowerPC chips essentially disappeared. But Intel is still making and shipping processors, meaning that we (and Apple) can still see what might have been if the switch had never happened.
Some of Intel’s updates this decade have been quite good. The current Core Ultra Series 3 chips, in particular, are its most competitive in years, based on their CPU performance, graphics performance, and power efficiency. But I’d take Apple’s steady, consistent drumbeat of generation-over-generation improvement any day over Intel’s herky-jerky rollercoaster of refreshes, rebadges, and architectural overhauls.
Ditching Intel was a big risk for Apple, but so far, it’s been the right decision.