- Apple Intel transition
The Apple Intel transition was the process of changing the
CPUof Macintosh computersfrom PowerPCprocessors to Intel x86processors. The transition became public knowledge at the 2005 Worldwide Developers Conference(WWDC), when Apple Computer CEO Steve Jobsmade the announcement that the company would make a transition from the use of PowerPC microprocessors supplied by Freescale(formerly Motorola) and IBMin its Macintosh computers, to processors designed and manufactured by Intel, a chief supplier for most of Apple's competitors. [Apple press release, June 6, 2005: [http://www.apple.com/pr/library/2005/jun/06intel.html "Apple to Use Intel Microprocessors Beginning in 2006"] ]
Apple's initial press release indicated the transition would begin by June 2006 and finish by the end of
2007, but it actually proceeded much more quickly. The first generation Intel-based Macintoshes were released in January 2006, and Steve Jobs announced the last models to switch in August 2006, with the Mac Proavailable immediately and with the Intel Xserveavailable by October 2006. [ [http://macworld.com/news/2006/08/07/liveupdate/ "WWDC Live Keynote Update"] ] The Xserve servers were available in December 2006. [cite web |url=http://images.apple.com/xserve/pdf/Xserve_TechnologyOverview12202006.pdf |title=Xserve Technology Overview|format=PDF]
*June 6, 2005: Apple announces its plans to switch to Intel processors at the Worldwide Developer Conference and released a Developer Transition Kit, a PC with a
Trusted Platform Modulein a modified Power Mac G5case, to all Select and Premier members of the Apple Developer Connection at a price of $999.
*January 10, 2006: Jobs announces the first two computers in this series, the 15"
MacBook Proand iMac Core Duo line, both using an Intel Core Duo chip and offers to trade in the Developer Transition Kits for iMacs.
*February 28, 2006: Jobs announces that the
Mac mininow also comes with an Intel Corechip, in either the Solo or Duo varieties.
*April 5, 2006: Apple announces the release of Boot Camp which will allow users of Intel based Macs to run
Windows XP. [ BBC Newsarticle, April 5, 2006: [http://news.bbc.co.uk/1/hi/technology/4880022.stm "Apple makes Macs run Windows XP"] ]
*April 24, 2006: Apple announces the 17" MacBook Pro, replacing the 17"
*April 27, 2006: Intel announces that processors with the
Intel Core microarchitecturewould be released months sooner than previously thought.
*May 16, 2006: Apple announces the 13"
MacBook, replacing both the iBookline and the 12" PowerBook.
*June 26, 2006: Intel announces the Xeon 5100 series server/workstation CPU. [
MacWorldarticle, June 26, 2006: [http://www.macworld.com/news/2006/06/26/woodcrest/index.php "Intel rolls out 'Woodcrest' chip"] ]
*July 5, 2006: Apple announces a special educational configuration of the
iMac, replacing the old G4 eMac.
*August 7, 2006: "Transition Complete" - Apple announces the Intel-based
Mac Pro, replacing the Power Mac G5, and Xserve, replacing the Xserve G5, at the Worldwide Developers Conference; both use the Xeon 5100 series ("Woodcrest") processors.
*December 31, 2006: Developer Transition Kits were expected to be returned to Apple within a week of this date.
The Macintosh line underwent a similar transition between
1994and about 1996, when Apple switched from Motorola's 68Kseries of chips to IBM/Motorola PowerPCprocessors, developed jointly by Motorola, Apple, and IBM. This took several years, during which Apple produced versions of the Mac OSthat could run on either platform, introduced fairly low-level emulation of the 68K architecture by the PowerPC models, and encouraged third-party developers to release "fat binaries" that could run natively on either architecture.
More recently, Apple has transitioned the Macintosh from the earlier
Mac OSto Mac OS X. This transition also took a number of years (a small percentage of older Macintoshes still run the earlier operating system), and was facilitated by the inclusion of Classic, an environment in which an instance of Mac OS 9could be run, permitting the execution of programs that had not been ported to Mac OS X, as well as the introduction of Carbon for Mac OS 9 and Mac OS X, allowing programs to run natively on either system.
A long-rumored internal project within Apple (rumored to be called "Marklar"), was designed to ensure that builds of Mac OS X remained largely as portable as its predecessor
NeXTSTEP, so as to compile for both PowerPC and x86-class processors. Jobs confirmed this, stating that every version of OS X had in fact been compiled for Intel processors as well as PowerPC. It is not publicly known whether Apple maintains current builds for any other architectures. However, since it has been [http://www.informationweek.com/news/showArticle.jhtml?articleID=197003973 confirmed] that at least three ARM processor cores are present in Apple's iPhoneproduct, it is strongly suspected an optimized version of OS X has been ported to the ARM architecture.
Jobs stated that Apple's primary motivation for the transition was their disappointment with the progress of IBM's development of PowerPC technology, and their greater faith in Intel to meet Apple's needs. In particular, he cited the performance per watt (that is, the speed per unit of electrical power) projections in the roadmap provided by Intel. This is an especially important consideration in laptop design affecting hours of use per battery charge.
In June 2003, Jobs had introduced Macs based on the PowerPC G5 processor and promised that within a year the
clock speedof the part would be up to 3 GHz. Two years later, 3 GHz G5s were still not available, and rumors continued that IBM's low yields on the POWER4-derived chip were to blame. Further, the heat produced by the chip proved an obstacle to deploying it in a laptopcomputer, which had become the fastest growing segment of the personal computerindustry.
Some observers were surprised that Apple had not made a deal with
AMD, which has in recent years become a strong competitor to Intel, sometimes introducing technologies more quickly than the traditional industry leader. AMD's shorter track record and smaller production capacity, and Intel's significant brandawareness among the consumers and ability to also provide Apple with complete motherboard designs, have been offered as possible reasons for the choice of Intel.
Benefits of the move
Advocates of the transition point out the potential for the new Intel Mac systems to run four classes of software at near native speeds: Mac OS X binaries, Java/.NET applications,
Unixapplications, and potentially now Win32/x86 applications. No other hardware vendor can offer more than three of these.
emulationsoftware such as DOSBoxor Virtual PCwas required in order to run x86 software on the Macintosh. Such software could now enjoy much more success with near-native performance through virtualization, such as is currently being done by Parallels Desktop for Macand VMware Fusion. For those customers wishing to achieve a more conventional environment, a dual, triple, or even quadruple boot solution would likely be possible on an x86 Apple device. Apple has already indicated they do not intend to take steps to prevent other operating systems being deployed on their new machines, and have subsequently released the Boot Camp software (including Windows drivers for Mac hardware) to facilitate setting up a dualboot system.
Although most games depend on the use of
DirectXAPIs not available on Mac OS X (on either processor type), it should be easier to port API-independent code now that developers no longer have to resolve endian issues associated with moving from x86 to PowerPC. Also developers no longer have to port x86 assembly to PowerPC.
Hurdles associated with the move
Reaction to the change
The announcement of Apple's intention to switch to Intel-based Macs caused concern because Rosetta, the PowerPC dynamic translator, when first announced, only emulated a G3 at 60-80% of a similarly powered CPU's clock speed. Apart from this, Classic, the
Mac OS 9virtualization for Mac OS X, was not ported to the x86 architecture, leaving the new Intel-powered Macs incompatible with original Mac OS applications without a proper third-party PowerPC emulator.
The performance of Intel's
chipsets was a concern, along with the x86 architecture itself, and whether it would affect system performance and application quality. Other problems include endianness(see discussion, background, and etymology) and reduced floating point performance in real world applications relative to equivalent or contemporary PowerPC processors.
It was also feared that it may be possible for Windows and Windows applications to run natively on Mac hardware, possibly killing off Mac OS X and/or applications developed for it. There was concern that the early announcement of the change would cause an
Osborne effect, and there was the possibility that Intel could force Apple to use the Intel Insidebranding.
There were also fears that Intel, who took part in the development and implementation of the
USBserial bus, would force Apple to drop all development and support of its FireWireserial bus on all Intel Macs. That has not happened, and some analysts have questioned the legality of such a move should it occur.
Many of these fears were put to rest at Macworld 2006 with the arrival of the first Intel-based Macs. Rosetta was improved to offer much faster speeds than originally demonstrated (though benchmarks suggest that PowerPC code still does not perform as well under emulation on a Core Duo iMac as it does on a G5 iMac [Anandtech, 30 January 2006: [http://www.anandtech.com/mac/showdoc.aspx?i=2685 Apple Makes the Switch: iMac G5 vs. iMac Core Duo] ] ). Intel's new Core Duo CPUs perform nearly as well as the most powerful
Power Mac G5towers, and outperform the G5 chip in the 2005 model of iMac on both integer and floating point SPECmark tests.
Applications native to both PPC and Intel-based Macs such as Safari web browser were found to perform better on the Intel-based Mac than on the PPC-based Mac. However, pre-OS X applications will not run directly on Intel Macs. Pre-OS X applications can only be run on Intel Macs by using
emulators such as vMac, Basilisk II, and SheepShaver, though the lack of stability of these emulators severely limits their functionality.
Fears of an
Osborne effectwere dismissed after sales of Macs for the Christmas 2005 quarter saw an increase over the previous Christmas. Intel-based Macs like the MacBook, MacBook Pro, iMac, or Mac miniwere branded with a special brand created by Apple, and the "Intel Inside" marquee was not used.
There are questions over the extent to which Apple will retain control over the non-processor components of the system design. Apple is traditionally a systems builder, and some fear that Apple's
industrial designphilosophy may be affected if the company switches to non-Apple parts. Others note that Apple has slowly been switching to standard parts since the introduction of the PCI Power Mac in 1995, and say that using a non-Apple chipset in itself would not harm the Mac's image.
The new Intel Macs employ a new Intel technology for
firmware, Extensible Firmware Interface, not the Open FirmwareApple had been using. EFI removes the traditional PC reliance on the BIOSwhile providing more functionality. [ [http://developer.apple.com/documentation/MacOSX/Conceptual/universal_binary/universal_binary_diffs/chapter_3_section_10.html Apple's transition documentation: Extensible Firmware Interface] ]
The use of the x86 architecture allows Windows to run natively on Apple hardware, and opens the possibility of using the
Wine packageto run Windows executables directly. Some fear that the change will make Mac OS X a less valuable target for software developers, since Mac OS X users can use a dual-boot setup, or, perhaps, Wine, to run Windows apps instead. Others say that it could be a boon to switchers, since they would not have to leave their Windows applications behind while trying out Mac OS X. The idea of Mac OS X being available on regular PCs has also been discussed, but Apple has said that they will not allow regular PCs to run Mac OS X. It was previously thought that since XP is incompatible with the Extensible Firmware Interface, it would not be run on Intel-based Macs [ Engadget, 11 January 2006: [http://engadget.com/2006/01/11/no-xp-on-intel-macs-but-vista-is-good-to-go/ New Macs not XP friendly, but Vista is good to go] ] . Prior to the Boot Camp announcement, a prize contestOnmac.net, 16th March2006: [http://onmac.net/ Windows XP on an Intel Mac] ] resulted in a working solution for dual-booting Windows XP and Mac OS X on an Intel Mac. Microsoft has announced that Windows Vistawill not be EFI-compatible on 32-bit platforms, but the latest version of Boot Camp allows Vista to be installed on any Intel Mac.
Intel was seen among the Mac community as a purveyor of hot-running chips (especially the
Pentium 4). Apple themselves mocked the Pentium range in their "Toasted Bunnies" advertisements of the late 1990s. However, the Pentium Mchips, which were designed for laptop use, run much cooler than the Pentium 4. Apple claims the new Intel Core chips, which are based on the Pentium M microarchitecture, have dramatically better performance per watt than the PowerPC G4 and G5.
Finally, the relative quality of the x86 architecture has been discussed. Critics of the switch say that x86 was a poor choice because of its lack of
hardware registers compared to the PowerPC, and the lack of AltiVec(also known as Velocity Engine). Proponents have responded by saying that the x86 architecture has evolved greatly since the original 8086 was introduced, and that CPUs in general have combined RISCand CISC philosophies in their internal designs for some time, making the distinction obsolete. They also point out that improvements to coming versions of SSE may equal AltiVec, and that most programmers rarely deal with x86's peculiarities now because the compilerdoes the work.
The Core Solo and Core Duo chips are
32-bitdesigns. On August 7, 2006, Apple released the Mac Proand Intel-based Xserve, introducing Intel 64 (Intel's implementation of x86-64) architecture into the lineup through the use of the Xeonprocessor. As of August 7, 2007, all other computers in Apple's product line have been updated with the 64-bit Core 2 Duo.
While the current benchmarks comparing Core Duo to Core 2 Duo processors show very little difference when running in 32 bit, The 64 bit edge will become more of an issue with the release of OS 10.5 (Leopard), and when users wish to dual boot Windows Vista in full 64 bit mode.
Existing PowerPC applications
Java applications (that don't rely on
Java Native Interface), Dashboard Widgets, and scripts that execute inside an interpreter all work immediately on both processors and are immune to changes. OS X applications that can't be migrated run inside a PowerPC dynamic translator on Intel called "Rosetta." Rosetta was originally limited to a G3 instruction set, but now currently supports AltiVecand the G4 instruction set, leaving only the G5 additions unsupported. Rosetta is an instruction translator comparable to the 68K emulator that allows PowerPC Macintoshes to run pre-PowerPC code, rather than a virtual system like Classic; it does not require a second operating system to be loaded as a subsystem before the application can work.
A new version of
Xcodehas been released that supports the generation of Universal Binariesfor Intel and PowerPC, the new system's equivalent of the earlier 68K-PowerPC fat binaries. Cocoa applications can be ported simply by recompiling them and checking for endian problems. Carbon applications may require some additional tuning, but not of the complexity of the transition from Mac OS 9. Applications written using Metrowerks CodeWarriorsuite will need to be modified; those which use PowerPlantwill run after some code changes, described by Apple and Metrowerks. Metrowerksdoes not appear to have announced the future direction of its compiler suite after the transition, although it has sold its x86 compiler/debugger technology to "a third party."
Classic is not supported on the x86 architecture. This means that pre-Mac OS X software will not be able to run on Mac OS X out of the box, to which some users running older applications (such as
QuarkXPress4 and 5) have objected. (This also represents the first time in the history of the platform that applications dating from 1984’s original 128k Mac have been unable to run on a stock Mac.) However, third-party emulators, such as Mini vMac, Basilisk II, and SheepShaver, have been ported to Intel-based Macs, allowing some pre-Mac OS X software to run.
* [http://developer.apple.com/documentation/MacOSX/Conceptual/universal_binary/ Apple Universal Binary Programming Guidelines]
* [http://www.appleintelfaq.com/ Apple/Intel FAQ (unofficial)]
* [http://www.eweek.com/article2/0,1895,1909736,00.asp Intel EFI Open-source implementation, code-name 'Tiano']
* [http://www.apple.com/macosx/bootcamp/ Boot Camp, Apple's beta solution to dual-boot Windows XP]
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