MAC OS X Snow Leopard 10.6.2 SSE2-SSE3 For INTEL-AMD | 4.3 GB
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