Apple finalizes PowerPC divorce with OS upgrade

This story has been corrected. See below for details.

Apple, a company that's rarely namby-pamby about making technological changes, has put its foot down once again with its Snow Leopard upgrade to Mac OS X due in September.

When the new operating system arrives in September, it'll work only on Intel-based Macs. That means Mac OS X 10.5, aka Leopard, will be the end of the line for those with Macs that use PowerPC processors.

Though the move led to some teeth-gnashing among those who felt left behind, it's not unreasonable in practice.

First, it was four years ago that Apple first told the world it was switching from PowerPC chips to Intel's x86 chips. Even though PowerPC models arrived afterward and the first Intel-based Macs didn't start arriving until 2006, three years is still a long time in computing history. Anyone who hadn't upgraded by now isn't the sort who demands cutting-edge technology.

Second, much of what's important about Mac OS X 10.6 isn't consumer-oriented features, but rather underpinnings to let Mac software take better advantage of new processor directions--Grand Central Dispatch for multicore processors and OpenCL to use graphics chips for general-purpose computation. Although Apple sold high-end PowerPC-based machines with two dual-core processors that could benefit from Snow Leopard's abilities to juggle multiple jobs at the same time, it's likely that many people with that large a computing demand moved on to modern machines.

And supporting new operating systems on older hardware is expensive. Bug fixes and security patches must be tested on a much wider array of systems. The expense is even higher with the complexities of supporting multiple processor families.

What will PowerPC users miss?
Mac OS X 10.6 has other features, to be sure, and Apple drew more attention to them than to the lack of PowerPC support this week at its Apple Worldwide Developer Conference in San Francisco. For example, Snow Leopard gets built-in support for Microsoft Exchange servers, which will make Macs coexist more easily in corporate networks and let people avoid Microsoft's Entourage software. Also arriving is a method to more easily shift among one application's open windows is another, a faster and more flexible Finder to browse files, faster backup with Time Machine, and higher-resolution video chat.

But the way I see it, those extra features are more refinements than revolution, and the new low $29 Mac OS X 10.6 upgrade price (or $49 for a household with up to five Macs) is a good incentive to move people to an operating system that will help Apple as much as the customers themselves.

Infrastructure that will help tap into multicore processor power is important. I'm still not expecting any free lunch for developers--it'll still be hard to write software split into parallel chunks that run independently in separate threads--but providing an operating system foundation that handles some multithreading chores stands to help the Mac ecosystem broadly. The fact that the only Macs available today with more than two processor cores are Mac Pro models costing at least $2,499 indicates that Apple recognizes the today's limits of multicore chips for most users.

But Apple likes to focus on the future more than on the past, and it's clear that multicore chips are the future. Wringing performance out of them is crucial to the success of any software.

Breaking with the past
Maintaining backward compatibility is a tough act in the computing market, where hardware changes faster than customers upgrade. Microsoft, with larger market share, has extended support for elderly software such as Windows NT 4.0 and Windows XP, but Apple has been willing to draw the line on many other occasions besides the Snow Leopard change.

Here are some examples:

• The move from PowerPC to Intel chips was not Apple's first change. The company switched from Motorola's 680x0 family of processors to the PowerPC line in the mid-1990s. To ease the transition, Apple provided translation software that could run older programs for 680x0 chips on the newer machines.

• After leading the charge for years with 3.5-inch floppy disk drives that were significantly smaller than the 5.25-inch models in PCs, Apple ditched the built-in floppy drive altogether with the 1998 introduction of the iMac. Need a floppy? Get an external drive.

• Also going by the wayside with the iMac was the Apple Desktop Bus, which had been used to connect keyboards and mice. Apple embraced the USB technology that began its life on the PC side of the industry.

• FireWire, standardized as IEEE 1394, is perhaps something of an exception. The Apple creation had superior data transfer speed compared to USB, but Apple no longer embraces FireWire universally. Today, MacBook Pro laptops have FireWire ports while the MacBook Air doesn't and consumer-oriented aluminum MacBook models introduced in 2008 didn't.

• ExpressCard, which inherited the the expansion-slot throne from the PCMCIA standard, is another victim of Apple's calculus. The company's newly announced MacBook Pro line ditches it in favor of an SD Card slot for flash memory cards. Only a "single-digit percentage of customers" was using the ExpressCard slot, said Phil Schiller, Apple's senior vice president of worldwide marketing, in his speech at WWDC.

• When it comes to connecting external monitors, Apple anointed DisplayPort when seeking a successor to the mini-DVI port in earlier MacBooks, passing over an entrenched alternative to DisplayPort, HDMI (High-definition Multimedia Interface). Adapters can help bridge the gap, though, for those who need to support incompatible displays.

Innovation's consequences
Not everything is an either-or proposition. Apple's gradual transition to a 64-bit operating system--a transition it says Snow Leopard completes--was eased by compatibility for older 32-bit drivers so older hardware didn't suddenly break. In comparison, Microsoft has strained hard for years to try to get hardware companies to release 64-bit drivers to let Windows communicate with their products.

But often, change does come at the expense of last year's technology, and it can be rough on customers when companies decide it's time to move on. I recently sold off an old Vista-incompatible Wacom graphics tablet I'd used for a decade, long after the PC industry had abandoned the serial port it required, and I was sad to see it go.

But change comes, and when it does, Apple's relatively small market share and low penetration into businesses actually is something of an asset.

Microsoft has to update Internet Explorer 6, a browser introduced eight years ago, in part because so many businesses don't want to rework processes that rely on it. Apple can move ahead to Safari 4 in a much more liberated way.

Apple wraps itself in the flag of innovation, and if you're a Mac user, you should expect both the ups and downs of that philosophy.

Corrected at 7:26 a.m. PDT to reflect that Apple's sole remaining MacBook model does have FireWire support and 1:57 p.m. PDT to reflect that the household upgrade price is good for up to five Macs.