More on Snow Leopard’s Kernel

CNET:

Apple’s Snow Leopard operating system, released Friday, by default loads with a 32-bit kernel, despite running 64-bit applications.

While Mac OS X version 10.6 ships with a number of 64-bit native applications, the kernel itself defaults to 32-bit, unless the user holds down the “6” and “4” keys during boot time, at which point the 64-bit kernel is loaded. Only Apple’s X-Serve products, using Snow Leopard Server, boot into a 64-bit kernel by default.

“For the most part, everything that they experience on the Mac, from the 64-bit point of view, the applications, the operating system, is all going to be 64-bit,” Stuart Harris, software product marketing manager at Apple Australia said.

Harris said that at this stage there were very few things, such as device drivers, that required 64-bit mode at the kernel level but the option is available.

“But we’re trying to make it as smooth as possible, so people don’t end up finding that ‘oh, that doesn’t work’ because it’s not available yet,” he said.