Mac OS X Snow Leopard offers a slew of hidden features and lays the groundwork for big advances to come.
Snow Leopard is Apple's latest operating system release, making this the seventh version of Mac OS X (eighth, if you count the two versions of 10.4 "Tiger" that bridged the PowerPC-to-Intel transition). On sale for $29 beginning tomorrow, Snow Leopard offers slimmed-down code, a smaller footprint and a raft of under-the-hood technologies designed to bring additional stability and performance. It also lays a strong foundation for the future.
Nearly two years ago, in October 2007, Apple released Mac OS X 10.5 (Leopard) a full six months behind its original ship date. (Apple blamed the delay on the need to prepare for the launch of the first iPhone.) Leopard brought more than 300 new features and tweaks to Apple's long-evolving OS. With the release of Mac OS X 10.6 -- this time, Apple unveiled its new OS ahead of schedule -- Apple builds on the underlying technologies it began to unleash in Leopard.
What it didn't do is change the look. Unless users know where to look, they won't see much difference between Leopard and Snow Leopard. The vast majority of the changes are under the hood, but they position Apple to take advantage of hardware advances for years to come.
Apple has included new desktop background images, including this one of a snow leopard.
This time around, the value of Snow Leopard isn't based on a checklist of new features. In fact, according to Apple, there aren't many. Tacitly acknowledging that it's tough to get people to buy something they can't see, Apple reversed directions on pricing, forgoing the usual $129 upgrade fee for a significantly more consumer-friendly $29 (unless you're upgrading from Mac OS X 10.4 Tiger, in which case you'll pay $169 for the OS and a box set of Apple apps). For households with more than one Mac, Apple offers a five-pack Family Upgrade for $49.
To compare: Microsoft's Windows 7 Ultimate upgrade costs $219, and the full version is $319 (there's no Family Pack for the Ultimate edition). Why compare Apple's latest with Ultimate? Because on the Windows side, Ultimate is the full-featured version. Snow Leopard comes in just one full-featured version.
Will your hardware run this OS?
Snow Leopard has the distinction of finishing the job Apple started with Mac OS X 10.4: It's finally moving away from the old PowerPC based-architecture it dumped in 2005 when it moved to Intel processors. If you're not on an Intel-based Mac, Snow Leopard won't install.
If you're not sure whether your computer can run Snow Leopard, click on the Apple menu and check "About This Mac." If your processor is a PowerPC G4 or G5, your Mac cannot be updated with the new OS. Snow Leopard still runs older PowerPC-based applications, but it will not boot a PowerPC-based Mac.
For everyone else with Intel-based hardware, Apple requires 5GB of available disk space, 1GB RAM, and an optical disk drive capable of reading DVDs (or, in the case of the MacBook Air, a DVD drive accessible via Remote Disk).
For enterprise customers, a new operating system usually means compatibility issues with at least some mission-critical apps, and Snow Leopard is no different. IT departments will want to do some testing before rolling out Apple's latest OS, because it's almost certain that some apps will need updating. For example, Cisco Systems has noted compatibility issues with its VPN software when using Snow Leopard's optional 64-bit kernel; a Computerworld editor has confirmed that issue.
Even so, most major applications and software drivers appear to work as they should, based on our testing and reports from testers during Snow Leopard's development cycle.
Installation simplified
The Snow Leopard experience begins with the installation, which works a little differently than in the past. You can still start the Mac by holding down the C key to boot from the disc, but Apple has simplified the process.
Instead of offering several installation options as in the past, Snow Leopard is smart enough to upgrade your system without having to be told exactly how to go about doing it. And if you ever need to reinstall this OS, Snow Leopard will not write over system files which are more current than the ones being installed.
Now when you pop the installation disc into the optical drive, the installer offers just two basic options: a Utilities button that lets you run basic programs like Disk Utility and restore from Time Machine backups, and a Continue button that takes you through the license agreement to a window from which you select your hard drive.
Customizing options include Printer Support (with optional installs for Printers Used by This Mac, Nearby and Popular Printers, and All Available Printers); additional fonts; a host of language translations; X11 (the windowing system for Unix environments); Rosetta (which allows Intel Macs to use software written for PowerPC-based ones); and QuickTime 7 (for compatibility with older media formats).
If a program (such as Mail Status Control) requires Rosetta, Software Update will offer to install it.
After choosing where to install the new OS, Snow Leopard will copy a large chunk of the data needed for installation from the DVD to your hard drive. That helps speed up the whole process -- Apple says it's 45% faster than the old installation routine because the installer reads the data copied to your hard drive rather directly from the DVD.
About halfway through the installation, the Mac reboots and finishes up the task at hand. You may notice that the screen goes dark during the installation. That's because the whole process is automated and you don't have to monitor what's happening. If you move the mouse or touch the trackpad, the screen wakes up and you can see where things stand.
Note that you cannot install 10.6 onto a hard drive that reports a S.M.A.R.T. failure. If a power outage occurs during installation, the installation picks up from where it left off.
After the installation is done, you get the traditional Apple intro movie and registration, and a desktop that looks just like Leopard: same menu bar, same Dock, same translucent menu at the top of the screen, and the same space-themed background.
Apple made few changes to the overall look of its OS; this screenshot was taken using the Grab application.
Fear not: Snow Leopard has some serious changes, even if they're not apparent.
What's waiting under the hood
Upgrading to Snow Leopard gives you additional hard drive space. Because it removes all of the old operating system files -- in previous OS X upgrades they used to go into a "Previous System" folder -- hundreds of megabytes, if not gigabytes, of space are freed up. The OS also takes up less room because the Universal code that was built into Tiger and Leopard to run PowerPC Macs is no longer needed, since Snow Leopard is Intel-only. According to Apple, most users will gain back 6GB of space. (AppleInsider delved into this issue right after Snow Leopard was announced in June 2008.)
While there are a few UI changes, the true value of Snow Leopard lies in the technologies waiting to be unleashed in applications: the ability to run programs in 64-bit mode, the use of OpenCL and the incorporation of Grand Central Dispatch.
The use of 64-bit computing will greatly improve the capabilities of computers. For example, 32-bit software can access only 4 GB of RAM at a time; 64-bit computing expands that ceiling to 16 exabytes. That's 16 billion gigabytes. Plus, 64-bit applications run faster on computers with Intel Core 2 Duo or Xeon processors. They can crunch 64-bit code twice as fast per clock cycle as computers running in 32-bit.
Apple touts Snow Leopard as being first Mac OS to finally support 64-bit from top to bottom, although the default kernel status for all consumer Macs is the 32-bit kernel. Snow Leopard supports 64-bit applications even while running 32-bit drivers. Basically, whether the machine is booted into the 32-bit kernel or the 64-bit kernel, any application that can run at 64-bit will run in that mode automatically.
By having Snow Leopard boot into the 32-bit kernel, Apple improves software compatibility. That's because kernel extensions must match the kernel's mode, or they don't work. While Apple did a fine job porting over its native applications for 64-bit compatibility, there are still some third-party vendors that haven't released updates for their software (such as the aforementioned Cisco VPN software) yet.
OpenCL, GPUs and Grand Central Dispatch
Another technology new to Snow Leopard is the OpenCL standard (download PDF), which promises to speed things up without any changes to your hardware needed.
While CPU manufacturers have shifted from increasing processor clock speeds to adding more cores to processors, graphics chip makers have continued pushing the boundaries to boost the processing power behind their graphics cards. Years ago, Apple began offloading animation effects from the CPU to the graphics processing unit (GPU), freeing up the main processors for actual data-crunching.
Every version of Mac OS X in recent years has increasingly utilized the GPU for computationally expensive tasks. In 2006, Apple unveiled Core Image and Core Animation with Mac OS X 10.4, technologies that allow real-time image and video effects to be handled by the graphics cards. With Snow Leopard, Apple takes GPU acceleration to another level by developing and publishing an open standard to offload even more work to GPUs.
Enter OpenCL, a language and runtime framework that allows developers to crunch any data-parallel algorithms on any free processing core, automatically, without needing to code for specific circumstances. The best part for Mac owners is that OpenCL works with all GPUs and CPUs available in Apple's current line-up. The best part for developers is that only the most performance-intensive aspects of their software need be rewritten to take advantage of the new technology.
While OpenCL bridges the gap between software and the available processing cores on a computer, the new problem is how to account for all these cores and software instruction threads.
That's where Grand Central Dispatch (GCD) comes in.
Grand Central Dispatch is the foundation for keeping everything running smoothly; it acts like a built-in air traffic control center, dynamically adjusting computer workload based on available hardware and resources. If the resources are available, GCD speeds things up. If the computer is busy, GCD backs off. In concert with OpenCL and 64-bit, Grand Central Dispatch should lead to a big jump in performance and optimization as applications are updated.
Snow Leopard includes new account avatars. The desktop background image in this picture is also new.
continuedsource:computerworld
