Mac OS X on Intel FAQ

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This article or section is based on a forum post written by slb.


Will Macs switching to Intel processors mean viruses will be coming to Mac?


The insecurity of Windows is what causes the propagation of viruses. For instance, Mac OS X user accounts don't run with root privileges as in Windows. Windows also ships with a lot of ports open by default, while Mac OS X ships with none. However, while the design of the x86 architecture is, theoretically, more vulnerable to buffer overflow attacks, this is still mostly dependent on the software allowing such attacks to be executed. Modern Intel processors support "execute disable" bits set in memory to prevent certain buffer overflow attacks.

Furthermore, there are many operating systems already running on Intel PC's that see no viruses. Linux, for example, is a very popular alternative operating system that has seen almost no viruses because it has been designed to be secure, just like Mac OS X.

In short, your Mac will still be a Mac. It's just going to contain components made by a different company.

Are my Power-based Macs all obsolete and useless now?


In fact, they'll likely be supported for years and years. NeXTSTEP, the ancestor of Mac OS X, supported "fat binaries," which are single application bundles that contain executables compiled for multiple platforms. This means one app that can run on different processors freely.

Mac OS X also supports this, and Jobs called them "universal binaries" in the keynote. This means application developers can automatically compile a single version of the app that will run on either PPC or x86 Macs. It will happen invisibly to end users.

Your Mac is still a beautiful Mac that will continue to run new software for several years. At the WWDC 2005 keynote, Steve Jobs informed developers that they would be supporting both platforms for a long time to come.

Huh? Universal binaries?

Applications in Mac OS X are just folders with a certain extension. Finder treats them as a single entity. Inside the folder are all the resources for that application, including the executable file, which contains the code for the application. In a universal binary, this executable contains code for both PowerPC and Intel processors, allowing it to run natively in both. It should be noted that universal binaries contain just one executable file with code for multiple platforms, rather than a separate executable file for each platform as was the case with NeXTSTEP FAT binaries.

Can I copy apps from Mac OS X PPC to Mac OS X Intel and vice versa, and will they run on either machine?

It's too early to know for sure, but the Mac OS X installer will reportedly strip out the unneeded architecture from an application when you install it, saving disk space, although others see this as unlikely. More on this when developers learn how it all works.

What about my older PPC apps? What if they're not recompiled for new Intel Macs?

This is what Rosetta is for. Rosetta leverages technology from Transitive Corporation, a company that has developed a way of translating machine instructions from one chipset to another with little to no performance loss.

For older apps that don't provide a universal binary to run on the new chips, Rosetta will translate the binary instructions and run the app. Newer Intel chips are likely to be much faster (3.2+ Ghz) and make up for potential drops in performance for these apps.

And, of course, today's Macs will continue to run new software thanks to universal binaries. Nobody is missing out, developers won't be abandoning PowerPC anytime soon.

Is this going to be a huge, painful transition?

This isn't the early 90s anymore, and this isn't the old Mac OS, which was very reliant on the old processors. Mac OS X is based on OpenStep/NeXTSTEP, which was already very portable and ran on x86, so the operating system is very flexible on multiple platforms. Apple has been keeping secret internal x86 ports of Mac OS X for the past five years.

API and compiler technology has improved to the point that the processor is much less relevant. This wasn't the case in the 90s. Because of universal binaries and PPC emulation for older PPC apps that aren't updated, Apple is making the process nearly invisible to end-users. All you'll notice is a much faster computer, and today's Macs will happily run the same software that will be running on Intel Macs, thanks to universal binaries.

Steve Jobs told CNBC, "It's not as dramatic as you're characterizing it." Ultimately, it's really not.

Speaking of which, what are they going to call the PowerMacs and PowerBooks now that we're moving from Power chips?

The "Power" in the names doesn't actually refer to the Power-based architecture, as the first Apple PowerBooks used the old 68k chip. The same goes for the G4, G5, and possible G6, designations of computers. Those are names, which although they relate to the chip used inside, do not necessarily demand that the chip in there be a PowerPC chip.

In January, 2006, Apple released the MacBook Pro to eventually replace the PowerBook line of professional notebooks, becoming their first Intel-based notebook. According to Steve Jobs, the name change was because Apple wanted "Mac" in the name, rather than to remove "Power", so it is unclear if the PowerMac name will also change.

Will new Macs require the "lawn mower" fans that PCs use?

The lawnmower sound of your average PC is due to the cheap design of that manufacturer. For example, the PowerMac G5 includes nine fans, but under normal usage is much quieter than a standard PC due to intelligent engineering and fan rotation throttling.

G5s generate a lot of heat and require a lot of power, so if you already tolerate the fans needed for the PowerMac G5, an Intel chip will be a big improvement.

Will Macs continue to use Open Firmware?

Apple's developer documentation states that Apple will not use Open Firmware in Intel-based Macs, but rather use an Intel technology called EFI (Extensible Firmware Interface). See Apple's Developer Documentation on EFI.

Will I be able to run Mac OS X on my Dell?


"We will not allow running Mac OS X on anything other than an Apple Mac." - Phil Schiller

Granted, many users have reported that they got Mac OS X to run on their PC, using developer copies of Mac OS X. However, this can be very problematic and it is not permitted by Apple. When x86 Macs start coming to market, it is likely that there will be some sort of digital rights management to keep Mac OS X from running on non-Apple machines - EFI will play a major role in this since it is aimed at preventing reverse engineering and provides a layer for software to access hardware resources.

Will I be able to run Windows/Linux/other x86 OS on my Intel Mac?

When the first Intel based Macs were released, it was revealed that they used EFI instead of BIOS, which is not supported by 32-bit versions of Windows XP or many other operating systems. This initially caused concerns that booting Windows on such a computer would be impossible. However, in March 2006, an open source solution was released to allow Windows to boot on an Intel based Mac, and on April 5 2006, Apple released Boot Camp to allow dual booting in either Mac OS X or Windows. Firmware updates released on the same day allowed these computers to boot using BIOS.

It is also worth noting that the Wine Project, created to run Windows applications unmodified on Linux, is being developed for Mac OS X on Intel, possibly negating any reason to install a full Windows operating system alongside Mac OS X.

For more information, see Booting Windows on the Mac.

Will it make Windows to Mac ports easier? Will it make games faster?

It will make little difference in porting Windows applications. As stated before, most of today's software development is dependent on the APIs used, not the processor. A Windows app using the Win32 API to display a dialog box will still need to be changed so that it uses an Mac OS X API to display a dialog box. Direct3D games still rely on DirectX and need porting to OpenGL.

Most of today's games rely entirely on the GPU for their advanced graphics, so the CPU is rarely the bottleneck anymore when it comes to framerates.

Will we be forced to re-buy software if we want to run x86 native? Will we be forced to run the app in emulation mode? What if the app is G4-G5 only?

These are all questions to ask developers. Free updates will probably be provided in most cases. Many developers will probably use the processor switch as an opportunity to release a major version update. The shareware community will probably keep up with Intel compatibility quickly and easily, as they did with Tiger compatibility.

Why is Apple switching?

Steve Jobs told CNBC:

"As we look out into the future, where we want to go is maybe a little bit different," he said. "We can envision some awesome products that we want to build for our customers in the next few years, and as we look out a year or two into the future, Intel's processor roadmap really aligns with where we really want to go much more than any other."
Mr. Jobs says Apple has another good year of Power PC-based Macs to come and that the switch will be a more "gradual transition," constantly moving his right hand in a waving motion from side to side. "Hopefully meeting with our developers a year from today, we'll have some Intel-based Macs in the marketplace. But it's going to take maybe a two-year transition."

In truth, IBM has been unable to fufill Apple's manufacturing demands in the past, and that IBM's inability to deliver faster and cooler G5s for PowerBooks and faster Powermacs is holding back the Macintosh line. Switching to Intel processors means Apple can continue to deliver upgraded Macs--including PowerBooks that cross the 3Ghz barrier.

Intel's philosophy for future processor families mirrors many of the advantages once held by the PowerPC architecture, including low-power and high-performance. Clock-speed (MHz/GHz) is no longer the defining, important factor in Intel's future processor families, as "Performance per Watt" takes center stage.

Will this really be a seamless transition?


Universal binaries provide developers the ability to ship one app that runs on both platforms without issue. Users of today's Macs and future Macs will still be running the same software.

Rosetta provides users the ability to run older apps that for one reason or another haven't been recompiled yet.

Macs are not suddenly going to become PCs. Macs will still be Macs. Mac OS X will be Mac OS X. Only the processor underneath will change.

Will there be an "Intel Inside" sticker on future Macs?

Although computer manufacturers are provided with financial incentives if they do so, they are not required to have the "Intel Inside" sticker on their cases. The initial introduction of Intel based Macs (iMac (Intel) and MacBook Pro) has confirmed the belief that Apple would not use the Intel logo on the new machines. Although the Intel based Macs do not have an Intel sticker on the machines, the cartons they're shipped in do have a sticker that mentions "Intel" - this, according to Apple, is to indicate to the average consumer that s/he is looking at a Mac that's new (and uses Intel processors) and thus avoid any confusion with the earlier PowerPC based models.

What does this mean for Apple's competition and other groups?

There are new things to consider with the use of an Intel platform, all of it speculation:

WINE, a free port of the Windows API written by independent developers, may allow Windows applications to run unchanged on a Mac at near-native speeds. Linux users already use such technologies to run Microsoft Office.

Virtual PC will be much, much faster because it won't need to emulate an Intel chip when running on an Intel-based Mac.

Groups like PearPC will probably attempt to get Mac OS X running under Windows with near-100% performance. It is entirely possible that this is doable, though one would assume Apple would be fully against it.

See Also