Snow Leopard Preview


Yes, It's Intel-only, but for anyone who does graphic- and processor-intensive work, Snow Leopard's full 64-bit support is good stuff.


WWDC 2009 was full of blockbuster announcements: New MacBook Pros, iPhone OS 3.0 and new iPhone 3GS hardware, and Snow Leopard, Apple’s next-gen operating system (Mac OS 10.6, if you’re counting).

And while there’s not a lot coming in the way of whiz-bang new features, it’s what’s going on behind the scenes that counts. In an interesting—and uncharacteristic—move, Apple will be selling the OS upgrade at a bargain-basement price. The $29 upgrade fee accomplishes two things: First, it accounts for the (apparent) lack of exciting new features from the user’s perspective. For the usual 129 bucks, people tend to want new stuff: new features, interface tweaks, and yes, new eye candy. Second, the modest upgrade fees help ensure that Mac users—who are traditionally very loyal to Apple’s OS upgrades anyway—will quickly move to Snow Leopard and in greater numbers than ever before.

Why the urgency? It’s because Snow Leopard has been entirely rewritten to take advantage of modern Intel hardware, and rapid user uptake will allow Apple to focus on moving its OS ever forward. Snow Leopard is also leaner than Leopard—Apple announced that a Snow Leopard install is 6GB smaller than Leopard. And Snow Leopard is faster as well. Apple has rewritten most of its own native apps to take advantage of 64-bit architecture, doubling the amount of data your Mac’s processor can crunch at one time, and tremendously increasing the potential of both existing Mac hardware, and whatever Apple’s got in the pipe.




Unfortunately, all this technological progress comes with a catch: Anyone still cruising along with PowerPC chips in their Macs will have reached the end of the road as far as OS X upgrades are concerned. Snow Leopard requires an Intel-based Mac.

Late-model Macs contain 64-bit processors, and Leopard already has limited support for 64-bit code. But most of the time, OS X and its apps parse data 32 bits at a time. While that doesn’t sound like much, keep in mind that’s 32 bits per clock cycle. A current midrange iMac accomplishes this nearly 3 billion times per second. Yes, billion, with a B. With Snow Leopard, however, Apple has rewritten nearly all of the native apps to take advantage of the 64-bit chips in late models Macs. So when it’s running 64-bit apps, your Mac will be able to process twice as much data as before, resulting in dramatic speed bumps for processor-intensive tasks. The only reason the world hasn’t already gone 64-bit is that applications must be written from the beginning to take advantage of 64-bit processing at the OS and chip level.




For all you non-computer-science majors out there, a bit is the smallest unit of digital data that a computer can recognize. It’s the proverbial 1 or 0. Eight bits equals the one byte required to store one English character. This article contains about 6,600 bytes of data, give or take a couple thousand bits. A kilobyte is a thousand bytes. 5.25-inch floppies from the Mac Classic era held 1.44 megabytes, or approximately 1,440 kilobytes. Grow that by several orders of magnitude, and you’re up to the now-common 1 terabyte hard drive, which holds a thousand gigabytes, 1 million megabytes, or 1 billion kilobytes. And, of course, all of that is approximate. Technically speaking, a kilobyte is 1,024 bytes, but for simplicity’s sake, digital data is commonly measured in factors of 1,000—which explains why your 320GB laptop drive only shows about 298GB worth of space in the Finder. Which brings us back to 64-bit processors.

So what will 64 bits do for you? First the bad news. It won’t make working with everyday apps—like a word processor, email app, or Web browser—any faster. Your brain is the weak link in that chain. But for apps that require serious processing muscle to make things happen, the 64-bit architecture is your new best friend. Everything from complex Photoshop filters to 3D rendering will get a major speed boost from the new code. Pro-level audio and video apps are also likely candidates for 64-bit rewrites. But if you’re dreaming of 64-bit Photoshop, don’t get ahead of yourself. Creative Suite 4, which Adobe released in October 2008, is a 32-bit app. The Windows version of Photoshop is built from 64-bit code, but unfortunately the Mac versions of Adobe’s apps are built on Carbon, an older Mac programming environment, which Apple has abandoned in favor of Cocoa. That means all the existing code needs to be rebuilt from the ground up. Adobe remains committed to 64-bit apps on the Mac, however, and has stated that a 64-bit version of Photoshop is on track for release as part of CS5.




The good news is that Apple is already using 64-bit-capable chips in its most current Macs. If you’ve got a Core 2 Duo processor, which Apple started using in 2006, you’re good to go (to check your Mac’s CPU, check About This Mac under the Apple menu). Older G5 processors are also 64-bit, but as we’ve said, Snow Leopard itself will only support Intel-based Macs.

Apple offered limited 64-bit support in OS 10.4, better known as Tiger. Developers have been able to write certain kinds of 64-bit code for your Mac, although they also had to support 32-bit architecture. Under Tiger, developers could write background processes that utilized 64-bit processing power, but data had to be passed on to a 32-bit GUI—the part of the app that you see and interact with.

Snow Leopard marks the first time that the OS and native apps will be written to take full advantage of 64-bit code. Apple reports that with the September release of Snow Leopard, “nearly all system applications—including the Finder, Mail, Safari, iCal, and iChat—are now built with 64-bit code.” Save DVD Player, Front Row, Grapher, and iTunes, every bit of code on your Mac running OS 10.6 Snow Leopard will be able to leverage 64-bit computing power. To see which of your current applications are 64-bit, run this Terminal command:


locate -0 app/Contents/MacOS/ | xargs -0 file | grep x86_64.


Aside from increased data-crunching prowess, another huge win for Snow Leopard’s 64-bit architecture is the ability to support more RAM. And when we say more, we mean lots more. Current Macs running Leopard can support up to 32GB of RAM, but the 32-bit applications that run on them can only address up to 4GB at a time. A native 64-bit app, on the other hand, can theoretically utilize up to 16 exabytes of RAM—that is, 16 billion GB. Snow Leopard itself will be ready to support a much, much smaller 16TB of RAM, but that’s 500 times more RAM than current machines can handle.

Bottom line: Increased processing power, more future-proof architecture, and the ability to handle more RAM than you could possibly ever need...for now. And, in case you’re wondering, at today’s prices, 16TB of RAM would set you back $195,200. Good thing the Snow Leopard upgrade is only 29 bucks.—Ray Aguilera

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