64-bit and what it will do for me?

[joerick]

I'm doing a bit of reading up on the Snow Leopard support. I've got a Core 2 duo in my MacBook Pro, which I understand can do either 64-bit and 32-bit. So I've got a couple of questions:

- Does a 64-bit kernel/OS mean that it will use twice as much memory as before? I ask because all the standard data types will have doubled their size.... or does it not work like that?

- Will any of the OS actually see a performance improvement? Are there any parts of the OS that would run faster with 64 bit numbers / memory greater than 4GB?

- Having read up about the Intel Core 2 Duo, a datasheet says that it is actually optimised for 32-bit applications... is this worrying?
http://download.intel.com/design/processor/datashts/318732.pdf

 

[Consultant]

There are dozens of threads on it, also, articles:

Road to Mac OS X Snow Leopard: 64-bit security
http://www.appleinsider.com/articles/09/01/16/road_to_mac_os_x_snow_leopard_64_bit_security.html

Road to Mac OS X Snow Leopard: 64-bit to the Kernel
http://www.appleinsider.com/article...c_os_x_snow_leopard_64_bit_to_the_kernel.html

Road to Mac OS X Snow Leopard: the future of 64-bit apps
http://www.appleinsider.com/article...x_snow_leopard_the_future_of_64_bit_apps.html

Road to Snow Leopard: twice the RAM, half the price, 64-bits
http://www.appleinsider.com/article...ard_twice_the_ram_half_the_price_64_bits.html

Road to Mac OS X Snow Leopard: 64-bits, Santa Rosa, and more
http://www.appleinsider.com/article...bits_santa_rosa_and_the_great_pc_swindle.html

Road to Mac OS X 10.6 Snow Leopard: 64-Bits
http://www.appleinsider.com/articles/08/08/26/road_to_mac_os_x_10_6_snow_leopard_64_bits.html

 

[Amdahl]

I'm doing a bit of reading up on the Snow Leopard support. I've got a Core 2 duo in my MacBook Pro, which I understand can do either 64-bit and 32-bit. So I've got a couple of questions:

- Does a 64-bit kernel/OS mean that it will use twice as much memory as before? I ask because all the standard data types will have doubled their size.... or does it not work like that?

Actually, only pointers double in size. This does mean memory usage goes up, but not too badly. The big gain (specific to AMD64 vs. x86) is that you have twice as many registers for programs to use, for the first time in over 30 years of 8086 history. This makes up for any losses in cache efficiency due to larger memory footprint.

- Having read up about the Intel Core 2 Duo, a datasheet says that it is actually optimised for 32-bit applications... is this worrying?
http://download.intel.com/design/processor/datashts/318732.pdf

It might be true, but it is nothing to worry about. It just means you'll have something to look forward to on your next computer, when they start shifting their design bias toward 64-bit code. Intel made the mistake of optimizing for 32-bit code when they released the Pentium Pro, and folks complained that Win 3.1/95 and current 16-bit apps didn't run as fast as they hoped compared to original Pentium. This time around, Intel is waiting for software to catch up first before they make design choices that hurt existing 32-bit code.

 

[lazydesi]

in easy terms all the applications will work fastly with less resources when compared to 32 bit

 

[ppc750fx]

in easy terms all the applications will work fastly with less resources when compared to 32 bit

No. It's not that simple.

 

[EB66]

No. It's not that simple.

i wish it was that simple "the road to snow leopard" is like reading a novel