Mac OS X Snow Leopard 10.6 - the story so far

Grand Central

Recognising the recent sea change in processors, with multiple cores rather than clock speed driving overall performance increases, Apple has developed 'Grand Central', a collection of technologies which it claims brings "unrivalled support for multi-core systems to Mac OS X." With Snow Leopard, the entire operating system is optimised for multi-core CPUs.

Apple describes Grand Central as a "parallel programming breakthrough" that "revolutionises the way computers deal with multi-core processors." As Steve Jobs told the New York Times, "The way the processor industry is going is to add more and more cores, but nobody knows how to program those things. Two, yeah. Four, not really. Eight, forget it."

With Grand Central, Snow Leopard breaks this impasse by making it far easier for developers to create third-party applications which take advantage of multiple cores. Reaction from Mac developers has been positive. "It almost makes me wish I had something to compute," quipped Daniel Jalkut. "Maybe I should write something."

Another under-the-hood feature that squeezes every last ounce of power from your Mac is OpenCL (Open Computing Language), which allows developers to "efficiently tap the vast gigaflops of computing power currently locked up in the graphics processing unit".

According to Apple: "With GPUs approaching processing speeds of a trillion operations per second, they're capable of considerably more than just drawing pictures. OpenCL takes that power and redirects it for general-purpose computing."

64-bit kernel

Snow Leopard also offers OS X's first 64-bit kernel, though for older Macs, 32-bit is also supported. Today's Mac OS can run 64-bit software, but does so using a 32-bit kernel. Having a 64-bit kernel offers significant advantages for the end user.

For a start, the OS can address huge amounts of installed RAM. According to Apple, Snow Leopard and the Macs of the future can enjoy "up to a theoretical 16TB, or 500 times more than what is possible today." This will make applications run faster by allowing more and more data to be stored in RAM, which is much quicker to access than the hard drive.

In the past, OS X's Finder has come in for considerable criticism. As it's one of the oldest parts of Mac OS, and is currently written in Apple's Carbon application programming interface (API), it's long overdue a make-over, and that's exactly what it's getting in Snow Leopard.

The new Finder is written entirely in Apple's more up-to-date API, Cocoa, which the company has been encouraging developers to switch to over the last few years. There aren't any drastic changes in the user interface, but streamlining Finder in Cocoa makes for a more robust, less bug-prone environment which provides a solid base for an expanded range of features.

Jeff Gaynard, MacSpeech's head of engineering and product development, sees the single API focus as a good thing. "Apple put so many great APIs out there with Leopard that developers haven't had a chance to fully take advantage of them yet," he said.

Exchange integration

One of the few new features offered by Snow Leopard sees Address Book, Mail and iCal benefit from integration with Microsoft Exchange servers. Apple had already licensed the Exchange ActiveSync protocol for the iPhone, but now it's coming to the Mac too. This is great news for businesses that use Macs alongside PCs on an Exchange server.

Now Mac users can sync their calendars, contacts and email and also access them away from the office. Although not particularly relevant to the home user, these features will do much to boost the adoption of Macs by businesses and organisations.

OS X's notepad application TextEdit also gets a new feature. From 10.6, it's to benefit from text auto-correction, whereby commonly mistyped or misspelt words are corrected on the fly.