How does Leopard detect 4GB?

[Deleted member 143938]

According to http://www.apple.com/macosx/snowleopard/ Apple is taunting 64-bit. If this is new, then that means Leopard is 32-bit, no? And if so.. how does it detect 4/6GB of RAM? I thought only 64-bit can do that

 

[gunnm74]

It's also a 64-bit OS. Not sure why they're touting it for Snow Leopard. Maybe they're just reminding folks that it's a 64-bit OS also.

http://www.apple.com/macosx/technology/64bit.html

 

[aznx]

Leopard is partially 64-bit. Snow Leopard is completely 64-bit.

 

[dr.stevil]

Leopard is partially 64-bit. Snow Leopard is completely 64-bit.

x2, atleast as far as I've read
it's able to get around it by using physical address extension (but it's more of a 'hack' than anything, for lack of better words)

 

[TheSandman2236]

Leopard is partially 64-bit. Snow Leopard is completely 64-bit.

You've got it.

 

[kirbyrj]

Any ideas on a Snow Leopard release date? Just wondering .

 

[TheSandman2236]

Hopefully before Christmas, maybe around the time when Win7 is released.

 

[kmeson]

Here's the poop, Leopard has a 32bit kernel but that makes little difference. 64bit compiled applications, run 64bit, use the 64bit ABI, can access 64bit registers, etc... Starting with Tiger, Apple began phasing out, deprecating, older APIs and migrating frameworks to 64bit. Tiger supported 64bit CLI applications. With Leopard full 64bit GUI support was added. Along with that came 64bit support for Quicktime, Cocoa, and numerous other frameworks.

Additional poop can be found here (64bit Transition Guide, pdf).

 

[kirbyrj]

Hopefully before Christmas, maybe around the time when Win7 is released.

I thought maybe it would have been sometime over the summer, but I've heard lots of different things.

Here's the poop, Leopard has a 32bit kernel but that makes little difference. 64bit compiled applications, run 64bit, use the 64bit ABI, can access 64bit registers, etc... Starting with Tiger, Apple began phasing out, deprecating, older APIs and migrating frameworks to 64bit. Tiger supported 64bit CLI applications. With Leopard full 64bit GUI support was added. Along with that came 64bit support for Quicktime, Cocoa, and numerous other frameworks.

Additional poop can be found here (64bit Transition Guide, pdf).

Thanks...that was pretty interesting.

 

[Grazehell]

It's also a 64-bit OS. Not sure why they're touting it for Snow Leopard. Maybe they're just reminding folks that it's a 64-bit OS also.

http://www.apple.com/macosx/technology/64bit.html

Mac OSX currently runs on a 32bit Kernel the other parts of it is 64bit therefore it is just a true 64bit OS.
Talk about being beaten to the punch.

I kind of expected the mac people in here to know this

 

[bobdole369]

Well the 3.2GB/3.5GB, etc limitation comes from the motherboard. Taiwanese designers thought it would be fun to put address space used by the PCI bus and whatnot starting at the top of the 4GB stack and counting down.

Vista uses software tricks to remap that, and its not possible with winXP, thus your motherboard limitations show up in XP.

Some motherboards do this in hardware - most do not.

I'm sure Leopard does the same thing that Vista does.