Sneaking in a few days before its promised September release, the tune-up for Mac OS X Leopard costs $29 for current Leopard users, and packs just enough punch to be worth your money. Apple is careful to point out that Snow Leopard isn't a complete system overhaul, but rather a collection of hundreds of smaller refinements to make Leopard run more gracefully. Hidden among smaller tweaks are some technical improvements that result in a smoother, easier-to-use Leopard with plenty for Mac fans to be excited about. The user interface and everyday tasks feel faster in general, although we didn't notice a substantive improvement in application performance.
Even if you're not a current Leopard user, the $169 package that includes Snow Leopard, iLife, and iWork is a steal for the system upgrade and two of Apple's major software suites, not to mention the long-pined-after inclusion of Microsoft Exchange compatibility. Finally you will be able to connect with Exchange Servers (without using Microsoft's Entourage), but only if your company is using Microsoft Exchange 2007; many still aren't. Snow Leopard is offered on a single install disk--there are no separate, tiered pricing structures to worry about--and you're getting every feature and technical enhancement available in a single install. Unfortunately, for those on PowerPC systems, Snow Leopard only works with Intel Macs.
Installation of Snow Leopard is dead simple and (according to Apple) up to 45 percent faster than Leopard using a newly designed installer that asks only one question during the process. On our test machine, the process took about an hour, including two automatic restarts. The default setting installs Snow Leopard without tampering with any of your saved files, music, photos, or documents. Mostly we had no problems, but on one test machine we needed to reinstall the OS when it had trouble rebooting. Fortunately the new installer is designed for safely reinstalling the OS in the event you encounter any hiccups during your initial installation. On our second try, the OS installed perfectly on our test machine and no files were harmed. PowerPC Macs are no longer supported with Snow Leopard, however; you will need an Intel-based Mac to install the latest Mac OS.
Those who want to do a "Clean Install" (starting fresh by deleting everything for minimal conflicts) still can, but unlike installations in previous versions of previous Mac OS X that offered the clean install as a primary option, you'll need to use Disk Utility to first erase the volume, then run the install. Apple explained to us that not everyone knows what a clean install is and often chose it, not knowing that they would lose their files. We're happy with that answer, as long as people still get the option in some form.
Apple also claims that Snow Leopard uses 7GB less space than Leopard because of better file compression paired with selective driver inclusion. According to Apple, Snow Leopard will locate any missing drivers on the Web for you. We had no need of any special drivers during our tests.
Apple says a few new technologies in Snow Leopard make it worthy of the upgrade alone, with several features that Apple says will boost performance. Because all new Macs come with 64-bit multicore processors, multiple GBs of RAM, and high-powered graphics processing units, all the major applications in Snow Leopard--including the Finder--have been rewritten in 64-bit to take full advantage of the hardware. (The 64-bit technology allows application developers to allocate more memory to complete tasks so that the software runs faster and more smoothly.)
Apple has also added what it calls the Grand Central Dispatch that manages data sent to multicore processors in an effort to maximize performance; Apple says the GCD will speed up any application task, from processing images in Photoshop to playing your favorite games. The addition of the GCD also takes away the need for software developers to spend as much time managing multicore processors.
Another new technology in Snow Leopard is OpenCL, which allows software developers to tap into the power of any onboard video cards (or GPUs, for graphics processing units) for general-purpose computing without the addition of enormous amounts of code. Like the GCD, these are improvements that will mainly affect software developers. But hopefully it will mean more and better-performing software for users in the future.
To put some of these claims to the test, we decided to pit Mac OS X 10.5.8 Leopard against Mac OS X 10.6 Snow Leopard to see how these new technologies affected overall performance.
In our anecdotal tests of performance within the Snow Leopard user interface (UI), the operating system seems faster and more responsive than with Leopard. Finder, Stacks, Expose, launching apps, and other everyday processes feel snappy. We didn't, however, notice any improvement in application performance.
Overall, we saw only a 2.5 percent slowdown in application performance from Leopard to Snow Leopard on our more processor-intensive performance tests, including our multimedia multitasking test, in which we measure the time for QuickTime to finish converting a short movie while iTunes is performing its own conversion of MP3 into AAC format in the background simultaneously. As this falls within our typical margin of error (5 percent), we saw no significant difference with application performance when moving from Leopard to Snow Leopard. (See the bottom of this review for performance charts.)
Snow Leopard includes a number of user UI improvements intended to make working with Mac OS X easier and more efficient. Expose, Apple's system for visually finding the window you want on a cluttered desktop, used to be relegated to the Function keys on your keyboard. Snow Leopard now makes Expose accessible from the Dock; just click and hold on a Dock icon to see thumbnails of all the open windows in that application. Hitting the Tab key lets you cycle through the preview thumbnails of each open application. Using Expose in the Dock is very natural and elegant, making us wonder why this wasn't already a feature in Leopard.
In addition to using Expose to find the right window, you now also have the ability to drag files from one application to another using the Dock. Let's say you want to add an image to an e-mail, but your desktop is full of open windows. In Snow Leopard you can go to the image, drag it to the Mail icon in the Dock, and your e-mail window will spring-load, allowing you to drop the image into place. Though the ability to drag and drop files in this fashion is nice, we're not sure it's much easier than attaching an image by browsing through your folders. Still, if you know the image is already on your desktop, it's probably the faster method.
Stacks got a much-needed upgrade as well. In Leopard, Stacks only listed a certain number of files and applications requiring you to go to a Finder window if your app wasn't listed. Similarly, if you tried to open a folder in Stacks, you were sent to the Finder. In Snow Leopard, Stacks comes with a scroll bar so icons are still easy to read and anything can be launched out of the Dock. Folders are now accessible within Stacks as well, so you'll be able to navigate to files within folders all without leaving the Stacks Window. These changes make Stacks much more useful than before and probably should have been available when Stacks was introduced.
While the Finder itself saw little in the way of interface tweaks, the way files behave in the Finder makes it easier to use. A zoom slider has been added to the lower right of Finder windows so you can zoom in on icons. An enhanced icon view has been added, letting you preview multipage documents and even play QuickTime movies without ever leaving the Finder window.
Preview now lets you preview almost any file, even if it was created with software you don't have on your hard drive. This means common file types from Microsoft Excel, PowerPoint, and even PDF files can all be previewed without owning the programs they were created in. As an added bonus, Preview in Snow Leopard provides accurate text selection to multicolumn PDF files using artificial intelligence to infer the layout of each page. This means that Preview recognizes that there are multiple columns in your document so you can select the text you want from any column.