Snow Leopard: The big improvements come under the hood

At one point in a briefing with Apple about the new Mac OS X 10.6 Snow Leopard, the conversation veered into surprising territory: We started discussing improvements to seemingly mundane items like ejecting disks and canceling file copy operations.

These weren't the major points to cover about the new Mac operating system, which went on sale Friday, but they did reveal the true nature of Snow Leopard: This release is focused on improving Mac OS X, not adding more features.

I've been waiting a long time for a software upgrade like this.

Mac OS X 10.6 isn't without its big improvements, but most of what's new is infrastructure. The operating system takes full advantage of the 64-bit capabilities of the Intel processors that run today's Macs, including most of the built-in applications.

For the most part, that means applications can use much larger chunks of memory (up to a theoretical 16 billion gigabytes) as they run, which in some cases — graphics-intensive programs or actions that require a lot of mathematical computation, for instance — can dramatically speed up performance.

Also new is Grand Central Dispatch and OpenCL support, a pair of technologies that take advantage of multi-core processors and the tremendous processing power of today's graphics cards.

In real terms, these technologies translate to a general speed increase throughout Snow Leopard compared with previous versions of Mac OS X. On my main Mac, a 2006 model MacBook Pro, most everything has more pep to it; I feel like Snow Leopard has extended its life span. Running Mac OS X 10.6 on brand-new machines feels more dramatic compared with Leopard.

Snow Leopard is definitely geared to new hardware, however. It works only on Intel-based Macs, abandoning the older PowerPC architecture. My MacBook Pro's ATI Radeon X1600 graphics card isn't supported by OpenCL, so I'm missing out on some performance increases.

Also, improvements delivered by Grand Central Dispatch and OpenCL in non-Apple software are likely to come later, as developers update their applications to take advantage of the technologies.

Other notable and nearly invisible improvements abound. When you download and open a file, the File Quarantine technology introduced in Mac OS X 10.4, which prevents downloaded applications from running automatically, can now identify known viruses and other malware. (Yes, Virginia, there are security risks on the Mac, just not remotely as many as under Windows.)

Simple installation

Installing Snow Leopard is more straightforward than with earlier versions. There's no Archive and Install option, for example; version 10.6 just installs over the top of version 10.5, with one restart of the computer in the middle of the process. The installer also accesses an Apple list of incompatible software and disables items that are known to not work under Snow Leopard (in my case, an ancient Sony Palm sync driver had been operating for years on my system).

And if the installation should quit midway because of a power outage or other unexpected event, the Leopard system remains unaffected; just rerun the Snow Leopard installer.

I could get lost in the little details:

• A new text-substitution feature automatically replaces things like "teh" with "the," and you can set up your own shortcuts.

• iChat supports video chats at 640-x 480-pixel resolution and does it using less bandwidth.

• The AirPort menu displays the signal strength of surrounding wireless networks (hold Option to reveal even more information about each one).

• When started up in Windows using Boot Camp, you can read (but not write) files on your Mac volume. (However, Apple does not yet provide Boot Camp drivers for Windows 7.)

• Services have been revamped, providing contextual options for handling text and other information between applications in a way that isn't as confusing and cluttered as earlier versions.

Beyond the little things

You see how easy it is to veer into these types of little touches? But back to the big picture; a few things will definitely affect people in noticeable ways.

The Exposé feature, which displays all open windows or all windows from one application, is now part of the Dock. Click and hold an application icon to bring up an Exposé of its windows, which appear in an orderly grid and include windows that have been minimized.

Also while in Exposé, hover over a window and press the space bar to view a larger preview of it, press Tab to switch between applications, or press Command-1 or Command-2 to organize the windows by name or by application.

"Wow," said a friend of mine who had so far ignored the feature, "I might use Exposé after all."

Mac OS X 10.6 adds Microsoft Exchange support to the operating system, which is great news for people who want to use a Mac but still access their companies' Exchange Server. Setup is simple: In Address Book, iCal or Mail, enter your e-mail address as a new Exchange 2007 account.

Snow Leopard uses the auto-discovery feature of Exchange to access your information and set up a new e-mail, contacts and calendars, with support for calendar invitations, meeting availability and the Global Address List.

QuickTime X is perhaps the most radical change from Leopard, featuring a minimal QuickTime Player interface and the capability to easily trim video clips. It also adds a screen recording function for capturing video of what appears on your screen.

However, if you've relied on the editing features of QuickTime Pro in the past, you won't find them here. QuickTime Player is now very much a consumer tool.

An optional QuickTime 7 install is available in the Snow Leopard installer to regain access to advanced codecs and encoding settings. It's automatically added if you have an existing QuickTime Pro license on your machine; you'll find the QuickTime Player 7 application stored in your Utilities folder.

Crash-free testing

These and other enhancements to Mac OS X don't look as good on marketing materials as big-ticket new features such as Time Machine (introduced in Leopard, sped up in Snow Leopard), but I'm much happier with better performance and stability. I should mention that in testing of beta versions of Snow Leopard for the past two months on multiple machines, it's never crashed.

Will people buy an operating-system upgrade that improves the infrastructure but mostly looks and behaves the same as what they're accustomed to?

I think they will, especially because it's priced at $29 for an upgrade (a five-license family pack costs $49, and the Mac Box Set, which also includes iLife '09 and iWork '09, costs $169).

How often in software do you get something that fundamentally makes something better instead of just making it bigger? When you're talking about operating systems, that answer is once — now.

Jeff Carlson is one of the contributors to the Practical Mac column in Personal Technology.