64-bit Leopard knocks spots off Vista

[Alpine]

Apple bites Vole

THE WIDELY REPORTED release of the next upgrade to Apple's operating system, Leopard, offers 64-bit support natively. This is of no shock to anyone keeping up to date with the goings on with this latest update to OSX.


Also unsurprising to Apple aficionados will be the extent of the 64-bit-ness of the underlying operating system within the Leopard release - something that hasn't been reported by non-Apple press as strongly as it might have been. Especially when comparing 64-bit support to that of Vista.

Windows Vista will come in a multitude of flavours: six at the last count. And it's said that all of these, bar the starter edition, will come with the added 64-bit support needed for modern CPUs - but the 64-bit versions will be completely different installable builds.

The 64-bit installation will come with a 32-bit emulation layer called WOW (Window on Windows, and nothing to do with orcs and elves) which will, as you can probably guess, allow you to run your old 32-bit apps on your shiny new 64-bit Vista, via emulation. 32-bit hardware drivers will not work.

Apple's previous offering - the Panther release of OSX - added rudimentary support for 64-bit, by expanding the virtual address space the kernel could use (programmers could use the increased memory space by juggling various memory address segments in their code). In Tiger, the current version of OSX, the OS has 64-bit specialised application libraries, of which there are few, and is still a half-way house to full 64-bit functionality. Upcoming Leopard takes this much further.

There will be just one version of workstation-based Leopard (plus an accompanying server edition), and it will come with 64-bit and full non-emulated 32-bit support.

Starting with Xcode 2.4, the OSX Universal binary format has been extended to support 32-bit and 64-bit for both PPC and Intel processors inside the same file, giving OSX quad universal binaries. Users don't have to choose between processor architectures nor 32-bit or 64-bit processors, either at the OS or application layers, it's all abstracted away from them - as it should be.

Note that the non-emulated support in OSX is for applications and drivers. 32-bit programs on Vista 64 need to work on WOW emulation to run in Vista, and 32-bit drivers are a no-no. Lack of driver support is the main reason Windows XP x64 hasn't been widely adopted, and why the Vista fudge will ensure hardware incompatibilities between the two Windows versions remain for sometime to come. This is quite a boon for OSX, and one that should be highlighted frequently and often.

The INQuirer