The majority of developers compiling for Intel support will already be using Xcode, meaning that continued PowerPC support is also as simple as a checkbox.
See here for more details.
What about 64-bit computing?
Apple has not forgotten about 64-bit computing, or x86-64 (x64/EM64T). However, Apple is trying to make the initial phase of the transition as simple as possible. 64-bit is a requirement for systems utilizing more than 4GB of RAM, which will be a necessity for some applications; Apple knows 64-bit capability is a requirement for many customers, particularly in professional, server, and enterprise environments. The Intel Core Microarchitecture[7.1] processor family is 64-bit.
Core 2 Duo ("Merom")
is the next generation dual-core portable processor and the pin-compatible successor
to the Intel Core processor family ("Yonah"), Core
2 Extreme ("Conroe") is the next generation dual-core desktop processor, Xeon
5100 Series ("Woodcrest") is the next generation dual-core server/workstation
processor, and Xeon 5300 Series ("Clovertown") is the next generation
quad-core server/workstation processor (pin-compatible with Woodcrest). It remains
unclear which of these processors Apple may use in future products, but Apple
is expected
to use the newest Intel processor technologies.
Apple is now using the 64-bit Xeon
5100 Series ("Woodcrest") in the Mac
Pro and Xserve product lines,
and the Core 2 Duo in the iMac, MacBook, and MacBook
Pro product lines. Also, Apple announced
at WWDC that Mac
OS X 10.5 (Leopard) and Mac
OS X Server 10.5 (Leopard Server) will have full 64-bit support (Leopard, Leopard
Server), throughout the OS, including Carbon and Cocoa applications.
What about AltiVec/VMX/Velocity Engine?
AltiVec instructions, because they are processor-specific, must be replaced on Macintosh computers using Intel microprocessors. You can choose from these two options:
Use the Accelerate framework. The Accelerate framework, introduced in Mac OS X 10.3 and expanded in 10.4, is a set of high-performance vector-accelerated libraries. It provides a layer of abstraction that lets you access vector-based code without needing to use vector instructions yourself or to be concerned with the architecture of the target machine. The system automatically invokes the appropriate instruction set.
Port AltiVec code to the Intel instruction set architecture (ISA). The MMX, SSE, SSE2, and SSE3 extensions provide analogous functionality to AltiVec. Like the AltiVec unit, these extensions are fixed-sized SIMD (Single Instruction Multiple Data) vector units, capable of a high degree of parallelism. Just as for AltiVec, code that is written to use the Intel ISA typically performs many times faster than scalar code.
See Preparing Vector-Based Code for more details.
The Intel Xeon 5100 Series ("Woodcrest") processor in use in the Mac Pro and
Xserve features an enhanced 128-bit SSE3 vector engine.
Why did Apple pick Intel instead of AMD?
AMD was approached, but supply problems similar to those with IBM appeared
likely. Also, Intel has been courting Apple for many years. Perhaps some of
that effort has paid off. Further, this announcement was designed to be one
of political expedience, convenience, exclusivity, and simplicity. The focus
was to not scare the analysts and financial markets; those circles are happy
with the "Intel" announcement. Further, you must look at Intel's roadmap one
to two years into the future from Apple's initial announcement to see the types
of processors Apple will be using; they're not Pentium 4, but will represent
the advanced next generation of Intel's microprocessor designs, the first of
which are now shipping (Core 2 Duo, Core 2 Extreme, Xeon 5100 Series). Finally,
since Apple has shown it is willing to switch processor architectures entirely,
nothing prevents Apple from availing itself of the best x86 and x86-64 processor
technologies available from other x86 vendors once the x86 transition is complete
or well underway - including those from AMD, as do many other PC vendors.
Will an Intel-based Mac run Windows?
Yes!
On April 5, 2006, Apple made a public preview of Boot
Camp available (press
release, FAQ),
a Windows dual boot solution that allows the use of Windows XP Service Pack
2 (SP2) on all Intel-based Macs. Apple also provides Windows drivers for the
hardware specific to Intel-based Macs, for items such as ethernet, wireless,
video, and so on. The Windows environment runs at full speed, and can even
be used for modern high-end games and other graphics intensive software, or
any software at all that runs under Windows XP. When booted into Windows XP,
an Intel-based Mac is literally a real Windows PC in every respect. Boot Camp
will be a standard part of Mac OS X 10.5 (Leopard).
One June 16, 2006, virtualization company Parallels announced
its Parallels Desktop (formerly
Parallels Workstation) virtualization product for Intel-based Macs. Parallels
is a hypervisor-based
(with a kernel module) virtual machine solution already shipping for Windows
and Linux, and is the first desktop virtualization product to support Intel
VT/Vanderpool CPU "partitioning". Its price is $79. Parallels has a long list
of officially
supported guest OSes, and that is just the ones that are officially supported;
it will run almost any x86-based OS.
On August 7, 2006, virtualization company VMWare announced that
they will be shipping a virtualization product for Intel-based Macs, under
the name VMWare Fusion. As of December 22, 2006, VMWare Fusion is now available
as a public
beta.
A preliminary manual
for VMWare Fusion is also available. VMWare Fusion is expected to ship
in 1Q2007. VMWare Fusion is expected to run any VMWare image, even images from
other platforms, as well as the numerous premade images made available via
the VMWare Technology Network (VMTN).
CodeWeavers also makes a product
called CrossOver, which
runs a limited selection of Windows applications under Mac OS X (and
Linux) without installing - or needing a license for - Windows itself. A public
beta of CrossOver Mac is
now available. To see
which Windows applications CrossOver supports, visit the Crossover
Compatibility Center.
---
The information below was written before the introduction of Boot Camp and Parallels, but is included for reference.
There was a previous solution for running Windows XP SP2 on Intel-based Macs;
see Windows XP on Intel-based Macs.
This same solution is also said to work with Windows XP Media Center Edition 2005 and Windows Server 2003.
This method requires burning special Windows installation discs, and is currently
a rather involved process. This solution
is essentially obsoleted by the official Apple solution above. The solution
worked very well, and yielded a machine that could easily boot between a
full Mac OS X environment and a full Windows environment, each taking advantage
of the full speed of the computer.
Another solution appears to be in the works from Amit Singh of Google (and
previously of IBM Almaden Research Center),
of kernelthread.com fame and author
of Mac OS X Internals. His group has devised
a method to allow legacy, or BIOS-based, booting on Intel-based Macs,
which they're calling "BAMBIOS". This means operating systems that currently
only support legacy booting, such as many Linux distributions that don't
yet support EFI, or products like Windows XP and the forthcoming Windows
Vista, will be able to boot unmodifed on Intel-based Macs. It is not yet
known when BAMBIOS will become available.
More background: The new Intel-based Macs use Intel EFI (instead
of BIOS or Open Firmware), and no shipping 32-bit versions of Windows support
EFI. While 64-bit versions of Windows support EFI, Intel Core Duo is
not a 64-bit processor. Windows Vista -
the next generation of the Windows operating system also known by its codename, "Longhorn" -
was expected to support EFI, but Microsoft has revealed that the 32-bit version
of Vista will not support EFI when it ships[10.0].
It is likely that a future version of Windows will be able to be installed
more directly.
However, since the new Macs will be an Intel x86 architecture, it is also
very likely that there will be Virtual PC-like
products that run Windows and Windows applications in a virtual machine environment
at or near the native speed of the hardware; that is, just as fast as if
Windows were running on that actual hardware. It is also possible to support
DirectX, meaning that Windows games could directly run on Intel-based Macs
under virtulaization.
At Macworld Expo San Francisco 2006, Microsoft announced[10.1]
that it was committed to developing a native version of Virtual
PC for
Intel-based Macs. [Ed. note: Microsoft has since announced that it is
discontinuing Virtual PC. Parallels and VMWare both will be offering solid
virtualization solutions for Intel-based Macs, and VMWare is already a market
leader in this area.] VMware is
also developing virtualization products for Mac OS X. A virtualization
solution has the advantage of being able to run a full Windows instance side-by-side
with Mac OS X simultaneously, and will also allow support features like easily
sharing files between environments, copy and paste between environments,
and so on.
It is also likely that other environments for running Windows applications
without Windows, such as Wine/Darwine and CrossOver/CrossOver Office[10.2]
will become available.
Apple Senior Vice President Phil Schiller has also repeatedly said Apple
would not prevent users from installing Windows on Intel-based Macs, but
is also not interested in selling or supporting Windows:
After Jobs' presentation, Apple Senior Vice President Phil Schiller
addressed the issue of running Windows on Macs, saying there are no plans
to sell or support Windows on an Intel-based Mac. "That doesn't preclude someone from running it on a Mac. They probably will," he said. "We won't do anything to preclude that." -
06/06/2005 [10.3]
Phil Schiller, Apple's senior vice president of worldwide product marketing,
said in an interview Tuesday that the company won't sell or support Windows
itself, but also hasn't done anything to preclude people from loading Windows
onto the machines themselves. "That's fine with us. We don't mind," Schiller said. "If there are people who love our hardware but are forced to put up with a Windows world, then that's OK." Schiller
made the comments at Tuesday's Macworld Expo, where Microsoft also said it
had signed a five-year pact with Apple to develop versions of Office for
Macs and announced plans to release a version of Office that will be compatible
with Apple's new Intel-based computers. - 01/10/2006 [10.4]
"Apple has no desire or plan to sell or support Windows, but many customers have expressed their interest to run Windows on Apple's superior hardware now that we use Intel processors," said Philip Schiller, Apple's senior vice president of Worldwide Product Marketing. "We
think Boot Camp makes the Mac even more appealing to Windows users considering
making the switch." - 04/05/2006 [10.5]
Will an Intel-based Mac run Linux, BSD, or other UNIX variants?
Yes. Red Hat, for example, has announced
it will support Intel-based Macs with Red Hat Enterprise Linux and Fedora Core.[10.0.1]
Other vendors have made similar statements.[10.0.2]
However, it will take some time for the various distributions to add support
for Intel-based Macs to their products.
With virtual machine solutions such as Parallels Desktop and VMWare Fusion,
any supported x86-based operating system can be run in a virtualization environment
on Mac OS X.
Does the Intel Core family processor in the Intel-based Macs support Intel Virtualization Technology (VT)/Vanderpool/VMX?
Yes. As can be seen here,
the "VMX" flag, which represents the Intel
Virtualization Technology (VT, also known as Vanderpool) Virtual
Machine Extensions (VMX) support, is present. VT allows running multiple operating
systems in completely separate hardware "partitions" on a single system. Previously,
there was a bug in the firmware of some Mac minis, which left VT disabled.
This issue has been reported to Apple. More
details.
Does the Intel Core processor in the Intel-based Macs support Intel Hyper-Threading Technology (HT/HTT)?
No. Hyper-Threading Technology (HTT) is a feature of the Pentium 4 microarchitecture.
The next generations of Intel processors also do not include HTT, but will
feature support for multithreading in general. HTT is a specific form of multithreading. More info.
Why would someone want to natively run Windows on an Intel-based Mac?
The real benefit to most people will come from running Windows alongside Mac
OS X in a "virtual machine" (VM) environment, in a window or even full screen,
for example with a hotkey to switch back and forth between Mac OS X and Windows.
To many users who prefer Mac OS X, particularly in enterprise, academic, and
research environments, but who also have the occasional applications (usually
administrative) that require Windows, this configuration would be very desirable.
And in this configuration, Windows wouldn't be running in emulation, but it
would be running at essentially the native speed of the underlying hardware
(with the exception of graphics and disk I/O performance). It will be much
faster than any emulation ever has been, and there will no doubt be several
open source (QEMU,
Xen, WINE) and commercial (VMware, Parallels)
that will allow running Windows (or Windows software) in various capacities.
Intel's Virtualization Technology (VT), allowing multiple operating systems
to run in separate hardware "partitions" on one processor, make these
prospects even more efficient and exciting from a technical standpoint. That
scenario will happen; it's only a matter of time of the software coming to
the platform now that the Intel Macs are shipping.
As to the question, however, of why someone would want to install Windows directly,
or "dual-boot", here are some answers:
Gaming. This is probably the primary reason. Since even virtual machine solutions typically still emulate some aspects of video, to get the full performance Windows still has to be running natively directly on the hardware.
Best possible performance. For those who want Windows and their Windows applications to run as best as they possibly can, again, running Windows directly is required.
A desire to run Windows (for whatever reason, whether it be preference, desire, necessity, etc.) on quality Apple hardware, while also having the option to run Mac OS X.
Other applications for which direct hardware access is required.
Becuase you can. No reason at all other than to "do it".
There are many other arguments for Apple's x86 transition being a potential trojan horse into environments that otherwise avoided Apple hardware because of requirements for Windows. Being able to run Windows in supported VM environments, such as VMware, could be a huge boon to Mac OS X/Apple adoption in certain sectors. The ability to directly boot Windows, even if officially unsupported by Apple, is also very attractive to some.
Will any x86-based PC run Mac OS X?
No.
Apple, via the Mac OS X license agreement, US law, and non-support of the product, will not allow Mac OS X to run on x86 hardware, at least in the near term. No doubt someone will hack it to run on various non-Apple x86 configurations (and there are websites dedicated to tracking just that), but this will be limited to a relatively small group of people due to the legal prohibitions and non-support, and such use will impact Apple minimally.
In the future, after the Intel transition is complete, it is possible that Apple could consider allowing Mac OS X to run on specific non-Apple hardware. But this is not likely to occur for the foreseeable future; if you want to run Mac OS X, you must still purchase an Apple computer:
Schiller said the company does not plan to let people run Mac
OS X on other computer makers' hardware. "We will not allow running Mac OS X on anything other than an Apple Mac," he
said. [11.1]
BusinessWeek has some further discussion and speculation on this topic in Should Apple Open Up?
Are PowerPC-based Macs now obsolete?
Not any more than any other PowerPC-based Mac is or ever has been. Support is eventually dropped for all older hardware in the current OS (for example, for PowerPC G3-based systems). Apple usually supports older hardware for an average of 6.5 years in the current OS, and there is no reason to believe that level of support will change, regardless of the processor contained in the hardware that supplants it.
Further, Mac OS X currently has an approximately two year lifecycle. Apple
has announced that Mac OS X 10.5 "Leopard" will ship at the end of 2006 or early 2007 (thus, Macworld Expo San Francisco 2007 in January seems a likely target). Apple has also specifically stated that Leopard will support PowerPC. Therefore, just from the official information we know today, it can be inferred that Apple will support PowerPC hardware with the current OS until at least 2009. Also, Apple has provided security updates for the version of Mac OS X immediately previous to the current release since Mac OS X 10.0. Therefore, we can further infer that security updates will be available for Mac OS X running on PowerPC until at least 2011. However, it is likely that PowerPC support will continue beyond this, given Apple's history of legacy hardware support in its operating systems. The official statement from Apple is that PowerPC support will continue for "a long time".
Other vendors, such as Microsoft, will continue producing software natively for both platforms as well. For example, on January 10, 2006, Microsoft formally committed[12.1] to continuting to produce Microsoft Office for Mac OS X on Intel and PowerPC platforms for a minimum of five years.
I was thinking about buying a Mac. Should I not buy one now?
All of Apple's products now ship with Intel processors; the transition to
Intel is complete. If a current Mac hardware offering is appropriate for your
needs now, it will be for its lifetime. Also, buying a Mac is still the only
way to run Mac OS X.
Will Mac OS X be more susceptible to Windows viruses and other malware, or other Windows-specific problems now that it will be running on Intel-based hardware?
No. It is the nature of the operating system, not the underlying hardware, that gives Mac OS X its security.
But if Windows (or another x86-based OS) is also run on an Intel-based Mac, it could be subject to the vulnerabilities of that operating system. However, when Windows or another OS is running in an emulation or a virtual machine environment, it is typically:
completely isolated from the network, operating "behind" the host operating
system
not used for traditional tasks typically used as attack vectors, like email, web browsing, and downloading files
usually not used as the primary operating system
able to be completely restored relatively easily and quickly from a default image, if compromised
So, this becomes less of an issue. It certainly could be vulnerable to issues
just as a full Windows machine would be, but there is less exposure for a variety
of reasons. Another key factor further mitigating problems is that, generally
speaking, the things that affect the Windows or other alternate environment
still won't affect the Mac OS X environment.
If Windows is used as a primary OS, or the computer is directly booted into Windows in a hypothetical dual-boot configuration, the machine could certainly be subject to any and all Windows vulnerabilities, and Windows security best practices should be maintained. In this configuration, any other OS installations (such as a Mac OS X installation) on the same machine would still generallty be unaffected by any potential issues.
Will an Intel-based Mac be just the same as any other PC? What will make it unique?
While Apple will use Intel processors in the Intel-based Macs, Apple will still control the design and features of the motherboard, the enclosure, and other included items. Apple's concentration on included features, industrial design, and quality workmanship will not change.
Will Intel-based Macs be as cheap as other PCs?
Even in the traditional PC world, there are wide variations in price for machines that may appear outwardly similar. Since Apple will likely continue to devote significant resources to quality, design, and features, Apple machines will likely continue to be more expensive than the cheapest PCs, but competitive with high-end quality offerings from other manufacturers.
Do Intel-based Macs use BIOS? Open Firmware? EFI? What is the partition scheme?
Shipping Intel-based Macintosh computers use Intel's new Extensible
Firmware Interface (EFI)[17.1].
The partition scheme is GUID Partition Table (GPT)[17.2],
part of the EFI standard. The default filesystem is still HFS+/Mac OS Extended
(Journaled), and all other conventional Mac OS X filesystem formats are available,
but they are now within GUID Partition Table (GPT) instead of Apple Partition
Map (APM). A Mac OS X 10.4.4 (PowerPC) system (or newer) can also read a GPT
disk, and a Mac OS X (Intel) system can read an APM disk. Apple's EFI implementation
supports GPT, APM, and NetBoot (PXE/TFTP)
for booting. While Mac OS X (Intel) only formats disks as GPT and will not
let Mac OS X be installed on an APM volume, this restriction is somewhat arbitrary,
as Intel-based Macs can indeed boot from APM volumes. Future systems could
again be unified in this respect.
(The Developer Transition Kit used an Intel BIOS, not a Phoenix BIOS as has been reported by some web sites.)
Information on EFI and GPT:
Intel Extensible Firmware Interface (EFI)
Unified EFI (UEFI) Forum
Microsoft: EFI and Windows Vista (PowerPoint)
Microsoft: Implementing EFI on 32-bit Systems (PowerPoint)
Microsoft: Unified EFI Update (PowerPoint)
EFI Wikipedia article
The Secrets of GPT (Apple)
Microsoft GUID Partition Table (GPT) reference
GPT Wikipedia article
More information on this topic from TidBITS
Apple knowledge base article
Can the EFI on Intel-based Macs be accessed?
Yes. Apple does not include an EFI shell or other tools for accessing EFI on
Intel-based Macs itself, but there
is a tool called rEFIt that
allows easy access to EFI functionality on Intel-based Macs. Perform at
your own risk.
---
The below is no longer thought to be an issue, but it is included for
reference.
Apple's
EFI implementation can be accessed by using the Intel
EFI Sample Implementation or the TianoCore
EFI Developer Kit (EDK). With the Intel EFI Sample Implementation, a graphical
EFI console or an EFI shell, among other features, can be used. These
interfaces allow accessing Apple's EFI functionality, similar to a BIOS interface.
Some
Intel-based iMacs have been left in an unbootable state after loading certain
EFI modules. To recover an Intel-based iMac from an unbootable state, the
following steps may be of assistance:
