Chapter 1. What’s New in Snow Leopard?

In 2000 the first iteration of Mac OS X was released to the public. It was called, without much imagination, Mac OS X Public Beta. Users who were eager to get in on the future of Macintosh were able to pay $29 for the privilege of being beta testers.

A lot has changed since Mac OS X Public Beta was released. Most of the changes were predictable—faster processors and more RAM—but some weren’t. One of the unpredictable changes was the switch to Intel processors. The switch to Intel left Apple supporting multiple chip architectures, a trick Apple managed with the addition of Rosetta for translating PowerPC instructions to Intel instructions for two versions of Mac OS X (Tiger and Leopard). Snow Leopard is the first version of Mac OS X to drop support for PowerPC-based Macs.

In Snow Leopard, Apple took the opportunity to further streamline the code behind the operating system. When you use Snow Leopard, you’ll notice faster start ups, a smaller disk footprint for the OS, and an all-around snappier feel.

What you won’t notice as immediately is all the effort Apple has put into making Snow Leopard a fully modern operating system. Apple has built-in support to take full advantage of today’s multiple core chips, the power of graphics cards, and the ever-expanding amount of RAM available to today’s computers. Snow Leopard isn’t just a nice release for this particular moment in time; it is a forward-looking iteration of Mac OS X that paves an easy path to the future.

Grand Central Dispatch

For years chip developers fought a megahertz and gigahertz war. To improve the performance of processors, chip manufacturers worked ceaselessly to produce chips that ran at ever-higher frequencies. That strategy came with heavy costs. As the clock frequency increased, the chips demanded more electricity and produced more heat. A really hot, power-hungry processor isn’t the most desirable solution for better performance, particularly if it is being used in a notebook.

The solution chip manufacturers created was multiple processing cores on the same chip. The idea being that by sandwiching two or more cores on a single chip, computers would effectively have multiple CPUs, thereby dramatically increasing performance.

The idea of adding more chips or cores to increase performance isn’t new; Apple was selling a multiple CPU system in 1997. The problem that multiple chip or multicore computers have faced isn’t one of raw computing power, but rather one of actually using all the computing power available to the machine. In days gone by, only programs specifically written for multiple processor machines could take advantage of multiple cores or chips. That kind of programming can be difficult to do, so developers often don’t take the time to make their programs multicore aware.

Grand Central Dispatch (GCD) addresses the problem of multiple processor usage by taking the hard work out of programming for multiple core systems. Instead, developers can program to make their applications GCD-capable. If a program is GCD-enabled, Snow Leopard will take care of the onerous chore of distributing processing tasks across the available cores.

The upshot for the end user is many more multicore-aware programs and a faster computing experience throughout the system. You’ll never know that Grand Central Dispatch is working behind the scenes to balance the loads between cores, but you’ll notice the bump in speed as more and more applications are able to efficiently use all the cores in your Mac.

True 64-bit Operating System

Chips aren’t just getting more cores, they’re also getting more bits. 64-bit computing isn’t new, but it was traditionally reserved for research settings and tech-heavy places where serious computing was going on. Now that 64-bit chips are available to anyone looking to buy a Mac, it would be an obvious waste of the chip’s capabilities if they were saddled with a 32-bit system.

Why is the computer world heading to 64-bits? One big reason is the amount of memory computers can routinely hold. A Mac Pro can hold up to 32 GB, but 32-bit applications can’t use all 32 GB; 32-bit applications can only address 4 GB of physical RAM. 64-bit applications can address (in theory) up to 16 billion GB.

In Snow Leopard, Mac OS X can now boot into a 64-bit kernel on certain systems (hold the 6 and 4 key down while booting). Even if you don’t boot into the 64-bit kernel, many of Snow Leopard’s built-in applications are 64-bit and run happily under the 32-bit kernel.

A 64-bit system isn’t just useful for the amount of memory it can address. With the 64-bit enhancements in Snow Leopard, applications benefit from hardware-assisted technologies to protect against malicious software.

In Snow Leopard, Apple has rewritten every application except Grapher, iTunes, DVD Player, and Front Row as 64-bit applications. So Safari, for example, can address more memory in your Mac and benefits from the security features as well. This means a faster, more secure computing experience when you’re using any of the updated applications.

Microsoft Exchange Support

If you work in a corporate environment, there is a good chance you use Microsoft Exchange. Microsoft Exchange is the extremely popular email server and collaboration service. Snow Leopard features out-of-the-box support for Microsoft Exchange 2007 servers. If your computing environment includes contacts, email, and calendars served up by Microsoft Exchange 2007, you’ll be able to stay up to date.


Any Mac that can run Snow Leopard (except for the older, single-core Mac Mini) has multiple cores, hence the usefulness of Grand Central Dispatch. But the CPUs aren’t the only source of number crunching available to your Mac. Your Mac also has a video card. The video is built into the core chipset on some models; on other models, video is handled by a separate, dedicated card known as the Graphics Processing Unit (GPU). Since that card holds a lot of independent computing power, particularly suited to certain types of computational challenges, it would be great if there was a way to tap the power for something other than the moments your Mac needs all that horsepower for gaming or rendering.

Open Computing Language, or Open CL, is Apple’s effort to squeeze maximum performance out of the hardware available. Developers will be able to tap the potential of video cards to aid your Mac with its processing duties. If you’re discounting the amount of power contained in a GPU, consider that the University of Antwerp created a supercomputer out of eight graphics cards. Even a single graphic card, if fed the right kind of processing problems, can significantly add to your Mac’s overall computing power.

After reading that, you might think if you run out and buy a Mac Pro with four video cards, it would provide you with unparalleled speed (it’s a top end Mac plus half a super computer, right?) but, at least for now, the payoff won’t be as big as you might expect. The kind of tasks that GPUs excel at aren’t the same that CPUs excel at processing. Consider this a bit of future-proofing: as the power of GPUs grow, developers will be able to take advantage of that power.

Smoking JavaScript

Most people never give a second thought to programming languages in general, and definitely don’t spend a lot of time thinking about a particular programming language. The Safari team isn’t most people, and they have spent a lot of time thinking about a specific programming language—JavaScript.

Why be obsessed with JavaScript and not, say, Pascal? Because JavaScript is all over the Web. JavaScript is part of the power behind AJAX (Asynchronous JavaScript and XML) and DHTML (Dynamic Hyper Text Markup Language). When you use a website that responds like a regular desktop application, there is a good chance that JavaScript is involved. Since it is such a web workhorse, speeding up JavaScript makes your browsing experience much better and the version of Safari bundled with Snow Leopard speeds up JavaScript substantially. Safari also includes some interesting enhancements, such as support for hardware-accelerated 3D operations right in the web browser.

Smaller Footprint

Mac OS X is slimming down. A Snow Leopard install takes less space than a Leopard install. How much less space? Well, that depends on how you configure the installation of Snow Leopard (if you choose to configure it at all). The smallest install of Snow Leopard requires a mere 8 GB of space, whereas using everything on the install disk version requires 11.6 GB of space. If you upgrade from Leopard to Snow Leopard, chances are you’ll find that up to 6 GB of disk space have been freed up.

Where did the space savings come from? Has Mac OS X been stripped of functionality to free up a little hard drive space? Thankfully, no. Remember that one key bit of functionality has been removed: support for the PowerPC platform. Previous versions of Mac OS X combined the software for Intel and PowerPC platforms into one big file. With the PowerPC support gone, these files are much smaller.


Rosetta, the technology that lets you run old PowerPC applications on Intel-based Macs, is still in there. So if you’ve got some old applications you need to keep running, you’re still in luck.

Application and Finder Enhancements

The lion’s share of the changes in Snow Leopard are more esoteric than most users are accustomed to, but that doesn’t mean there aren’t plenty of changes at an application level. Apple may have had all the company’s focus trained on the stuff that runs the applications you love to use, but a good bit of innovation and newness managed to slip into the applications as well. The changes, and how they affect what you do with Mac OS X, are explored more completely in the appropriate chapters, but you can get a quick overview by reading the rest of this chapter.

Finder Enhancements

What program do most Mac OS X users use more often than any other? The Finder. When you’re browsing through files or opening applications, you are using the Finder. The good news is that the Finder has been upgraded. It is faster in Snow Leopard (the Finder takes advantage of the underlying 64-bit nature of Snow Leopard and the multicore power of Grand Central Dispatch). But the Finder isn’t just speedier, the application also sports some new features. There are enough changes in the Finder to justify the $29 upgrade price of Snow Leopard, so a quick list of the biggest stuff will let you know what to look for. If you’re after more information on what has changed, Chapter 2 will reveal how to utilize the new features.

Better icons

The icons in Snow Leopard are bigger; they scale all the way up to 512×512 pixels. The initial reaction to icon sizes that large is one of befuddlement: what could be the point of such a large icon? A folder at 512×512 doesn’t reveal any more information than a folder represented at some arbitrary lesser resolution. In Snow Leopard, the large icon sizes are actually very useful. Look at a text document’s icon and you can actually read the text. Look at a spreadsheet and you’ll get a glimpse of the columns of numbers. If you’re rolling through your video folder, you can watch an entire movie in icon view.

More control over the sidebar

The sidebar made its debut with Leopard and provided a way to get at often-used folders, servers, disks, and devices. Useful but a bit cluttered if you didn’t take advantage of everything the sidebar offered. With Snow Leopard, the sidebar is more malleable. You can still add searches and the like, but now you can also delete the headers you don’t want to use. The change doesn’t have to be permanent—the moment you want the deleted header back, just drag the item to the sidebar and it will reappear.

The Finder can put that back for you

If you’ve done a bit of housekeeping on your Mac and have a Trash can full of items, you might decide you want to keep some of them after all. But where did that file in the Trash come from in the first place? In Snow Leopard, you won’t have to guess, because the Finder can put it back (right-click or Control-click on a file in the Trash, and select Put Back).

Application Enhancements

The Finder isn’t the only application in Snow Leopard to get upgraded. Almost every application has been rewritten for 64-bit compatibility. Some applications received more than just a new version number; they also received some improvements in performance or usability.


iChat is the video/audio/text chatting application built-in to Mac OS X. iChat has always been easy to use, but in Snow Leopard it has been significantly improved:

Better connectivity

Some iChat users were stymied by connectivity issues when using video chat. The reason didn’t have anything to do with the Mac, it had to do with servers and compatibility. iChat addresses these problems in Snow Leopard by fixing the incompatibilities or, if the problem can’t be resolved, by routing the chat through an AIM (AOL Instant Message) server. That video chat that didn’t work before will work now!

See more with iChat

In Snow Leopard, maximum resolution of a chat has been bumped up to 640×480 pixels. Apple calls that a 400% increase in resolution; to you it means more detail in your chat videos.

Less bandwidth

You’re laughing at the increased resolution because you’re worried about bandwidth? Part of the reason you can have such a huge chat window is because iChat under Snow Leopard uses much less bandwidth. A maximum resolution chat in Leopard requires almost a megabit of bandwidth to your ISP (900 Kbps to be exact), whereas iChat under Snow Leopard requires only one-third of that to achieve maximum quality.

Different statuses for every account

You probably have more than one iChat account. Perhaps you have one for work and one for personal use. With Leopard, all your accounts got the same status messages. If you wanted “Drinking beer, feel free to ring me” on your personal account, while tossing up “Working diligently on Chapter 2” on your work account, you were out of luck. In the latest version of iChat, you can pull that trick off. Just don’t give both iChat handles to your boss!

Quick Look enabled

People use iChat to swap files all the time; it is a convenient way of real-time file transfer, since you know immediately whether the file got to its destination. If you are on the receiving end of a transfer, you don’t have to open the file to get a look at what is inside anymore; you can use Quick Look to see an instant preview.


Preview started out life as a way to view PDFs. Not very exciting, but through the various iterations of Preview, the application became much more than just a PDF viewer. Preview will do everything from image retouching to scanning. The version of Preview that ships with Snow Leopard offers some substantial improvements:

Better text selection

If you’ve ever tried to copy text from a multicolumn PDF document you know it can be a hassle. The text isn’t selected in a rational manner. Preview fixes that. In the latest version, instead of selecting across columns when you don’t want to, you can actually just select the paragraphs, or parts of a paragraph, you want.

Improved scaling

Preview has been able to zoom and scale images and documents for quite some time. But the results of the scaling weren’t always ideal. Preview in Snow Leopard improves this behavior by using a new algorithm that decreases the annoying artifacts that bothered sharp-eyed users.

Annotations just got much easier

You could annotate PDFs and images with earlier versions of Preview, but the latest version makes it much easier. The version of Preview with Snow Leopard includes an annotation toolbar. Any time you want to make a note, click the Toolbar and point out the great (or horrible) stuff on a PDF.

Image correction histogram

In Leopard, Preview’s ability to correct images gained some improvements. In Snow Leopard, you get a live RGB histogram view for your image, which you can use to adjust color just like in iPhoto.

Import from scanner

Got a scanner but hate the bundled software? Don’t use it. You can now scan images directly into Preview and change them (or save them to edit in a different program).

QuickTime X

One application that got a lot of attention in Snow Leopard is QuickTime. More than just a new version number, QuickTime got a new name: QuickTime X. What’s new in QuickTime X?

QuickTime player

When you open a file with QuickTime, you won’t see the player you were expecting. Apple has reworked QuickTime player to make the controls invisible except for the moments you need them. If you’ve played a video with QuickTime in full screen, you have a good idea of what the new player looks like.

Capture media

Want to create a quick video of yourself? Of your screen? No problem in the new QuickTime. You can capture a video using your Mac’s built-in iSight or attached camera and post it directly to MobileMe or YouTube. Even better? When you’re posting the videos you make, you won’t have to worry about choosing the right codec or resolution, QuickTime X will take care of that drudgery for you.

Trim media

Is that video too long? Cut a few seconds off in QuickTime with the new media clip trimming capabilities.

Chapters with images

If you are viewing a multichapter video such as a DVD, you won’t be stuck with the often unrevealing chapter names when trying to navigate. QuickTime provides you with a thumbnail of a frame from the chapter to help you decide where you want to jump to next.

System Improvements

Some of the improvements in Snow Leopard are system-wide. These improvements are there without regard to the particular application you’re using and, in some cases, even when you’re not using any applications at all.

Faster Wake Up, Faster Shut Down, Faster Wireless Network Logon

No one likes waiting on their computer to do something. Snow Leopard decreases waiting and increases productivity. Joining a wireless network is faster using Snow Leopard, which is a nice bonus when you change hot spots frequently. If you put your Mac to sleep when you’re not using it, you’ll be happy to know that your Mac will wake even faster from sleep than it did when you were using an older version of Mac OS X. You’ll also appreciate the difference when you shut down, as Snow Leopard is noticeably faster when the shutdown sequence is invoked.

Split Pane Terminal

The Terminal in Mac OS X is either something you never use or something you use all the time. If you use the Terminal all the time, you’ll be pleased with the new split pane Terminal window.

Gamma Settings

Snow Leopard changes the default Gamma correction from 1.8 to 2.2. For some users, the change is purely esoteric; for users who work with color often, the change is substantial.

Snow Leopard Offers Even More

There’s more to Snow Leopard than what is listed here. You’ll find new niceties every time you use Snow Leopard. Some changes are subtle, some are minor; but taken together, the improvements in Snow Leopard add up to a more productive and pleasant experience.

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