Snow Leopard kernel only 32bits on 64bits Mac???
Snow Leopard will use a 32bits Kernel (exactly as 10.4 Tiger or 10.5 Leopard) on a majority of 64bits capable Mac!
64bits Kernel offers a boost of performance on the Kernel actions, such disk IO and buffering/caching, graphic drivers (including 3D OpenGL drivers), memory allocation and management, task management, etc. It comes from the fact that in 64bits mode, Core2 Duo processors offers twice the number of registers offered in 32bits mode, diminishing use of L! and L2 cache, and speeding code execution.
Intel Mac are not all 64bits enabled, firsts MacMini, MacBook, MacBook Pro & iMac that sport Core Solo or Core Duo processors are 32bits compûters, limited to 32bits mode, and will run Snow Leopard in 32 bits mode, and any software in 32bits mode.
The Mac that sport a Core2 Duo or Xeon processor are 64bits Macs, and on Tiger or Leopard, the kernel run in 32bits mode but applications may run in 64bits mode and access up to 32GB RAM (more useful on MacPro and latest MacBook Pro & iMac). But they actually don’t take benefits of a 64bits Kernel in term of performance.
Snow Leopard promised to give 64bits to all of us.On spetembre 2009!
That’s not the first time Apple promised it, it all started with PowerMac G5, the “most powerful 64bits computer”, more than 6 years ago, in June 2003!
Apple come back with the 64bits idea when launching Tiger at first and then Leopard, it was just marketing!
Now, 6 years after 64bits Mac, Apple say it will deliver a true 64bits OS, from the fundation (the Kernel!). It takes times, and 4 announces to go to true 64bits!
True 64bits? Depend on your Mac model, not it’s ability….
Naturally a MacMini Core2 Duo or a MacBook Air have 64bits processors, but it’s not really the target of 64bits computing.
But wait, what if MacBook Pro 13″ or firsts Mac Pro haven’t the ability to run the 64bits kernel, albeit bein equipped with Core2 Duo 64 bits processors and labelled “Pro”???
That’s the point…
Some Mac will run Snow Leopard on 32bits Kernel mode. MacBook Pro 13″, old 64bits MacBook Pros 15″/17″, first Mac Pro, old 64bits iMac, they couldn’t run Snow Leopard in full 64bits mode, wether they are labelled Pro or not.
Apple you are deceiving! Read the original story
PS: 64bits PowerMac G5, that was celebrated as best 64bits computer and even a “super-computer” by Apple won’t be able to run the first 64bits OS from Apple. Totally dumb!
