Is leopard a real 64bit OS?

[bofors]

leopard is 32bit, when snow leopard comes out, that's 64bit. 32bit os's can not address over 8gb's. 64bit os's will address up to 32gbs.

 

Here is what Apple says about Leopard being a 64-Bit OS:

 

64-Bit. Advanced precision in one OS.

 

Leopard delivers 64-bit power in one universal operating system. Now the Cocoa application frameworks, as well as graphics, scripting, and the UNIX foundations of the Mac, are all 64-bit. And since you get full performance and compatibility for your 32-bit applications and drivers, you don’t need to update everything on your system just to run a single 64-bit application.

Bridge the generation gap.

 

Since the entire operating system is 64-bit ready, you can take full advantage of the Xeon processors in the Mac Pro and Xserve. You get more processing power at up to 3.0GHz, without limiting your programs to command-line applications, servers, and computation engines.

Driver compatibility.

 

Because of its universal nature, with Leopard you don’t need a new set of drivers — or devices. New 64-bit applications work just fine with your existing printers, storage devices, and PCI cards. Even better, if you upgrade to new 64-bit-capable drivers, your 32-bit applications will also benefit from the increased throughput.

64-bit frameworks.

 

In addition to the POSIX and math libraries supported in Tiger, Leopard enables developers to build complete 64-bit applications using the Cocoa, Quartz, OpenGL, and X11 GUI frameworks. You can even use 64-bit Java on capable Intel processors. And the 64-bit and 32-bit versions of the libraries are built from exactly the same code base, to ensure a consistent experience for both developers and users.

 

64-Bit for Developers

 

Xcode 3.0 gives you all the tools you need to build true 64-bit applications, including:

 

* 64-bit addressing of up to 16 exabytes of virtual memory and 4 terabytes of physical memory

* Full 64-bit arithmetic

* 64-bit development tools

* 64-bit performance monitoring tools

* Seamless deployment

* LP64 data model

* Common source base support

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

 

Here is what Apple is saying about 64-Bit improvements in Snow Leopard:

 

64-bit

 

To accommodate the enormous amounts of memory being added to advanced hardware, Snow Leopard extends the 64-bit technology in Mac OS X to support breakthrough amounts of RAM — up to a theoretical 16TB, or 500 times more than what is possible today. More RAM makes applications run faster, because more of their data can be kept in the very fast physical RAM instead of on the much slower hard disk.

http://www.apple.com/macosx/snowleopard/

 

This appears to mean the following:

 

Mac OS X 10.5 moved a lot of the OS to 64-bit, and Snow Leopard finishes this. By having a 64-bit kernel, the OS can support up to 16 terabytes of RAM, larger numbers of running processes, and so on. Along with ZFS, moving the last parts of the OS to 64-bit helps future-proof Mac OS X and allow for (hopefully) bigger and better hardware to put it to work.

http://www.macworld.com/article/134042/200...pardserver.html

 

My 64-Bit question is: Will switching from running 2 GB of RAM to 4 GB or 8 GB result in a significant OS X performance increase in Leopard or Snow Leopard? I have previously run with 3 GB and 4 GB of RAM in Tiger and not seen any significant improvement in general OS X performance before. Note that I am not concerned about running applications that have a need for more than 1 GB of RAM.

[ColdStart]

By looking at a lot of the system processes and the types of binaries they contain as a fat file tells me that the majority of Leopard is not 64-bit.

One of the upsides of Snow Leopard is that the majority of the system processes, core services, and default applications are truly compiled as 64-bit.

 

It certainly makes me happy to know that more processes will be able to use my 8 GB of 1066MHz DDR2 RAM (had to get them, the deal on NewEgg was just too awesome.)

 

Kind of makes me wish that there was a site with a compiled list of 64-bit OS X applications.

 

This really made me sad when I read it:

http://www.appleinsider.com/articles/08/04..._till_v5_0.html

[new1phone]

Bottom line is that 32 bit OS can't (won't) use more than 4GB memory ..

XP/Vista 32bit won't .. so for what matters it's a 64 bits OS .. some people will be puritans and won't touch the ale .. but sam adams did :-) and we are thankful to him.

 

it's not the issue ..

[bonestonne]

so far (before snow leopard) OS X has been a HYBRID KERNEL. that means it has parts of both and can access more RAM and that's also why a Mac Pro may say that its OS is a 64 bit version, even if it's just 10.4.10. once Snow Leopard hits, there will be a fine line between the hybrid kernel and a true 64 bit kernel.

[vbetts]

But correct me if I'm wrong. Snow leopard will support PPC as well, which wouldn't make it a true 64-bit OS?

[netkas]

what a deal of this topic ?

 

32-bit leopard kernel has 32 and 64 bit commpage, 32 and 64 bit idt, and etc.

 

thx to PAE , 32-bit kernel allows 64-bit processes to use more than 4gb of ram.

 

and now, snow leopard kernel is macho fat file with next archs - x86/x86_64/ppc (no ppc64 yeah)

 

64-bit snowlepers kernel works same as 32-bit, only difference - kernel itself can use more than 4gb (will we ever need that ?) and there is no 64-bit video/audio/wifi drivers

 

both kernels works same for 32/64-bit processes.

 

32-bit processes does not have windows like problems, like kernel/application memory split, so 32-bit apps can use up to 4gb of memory (no 2gb limit).

[bofors]

64-bit snowlepers kernel works same as 32-bit, only difference - kernel itself can use more than 4gb (will we ever need that ?)

 

This again, is one of my questions about Snow Leopard.

 

Is there going to be a good reason to have more than 2 GB of RAM for general use with Snow Leopard?

 

Can Apple increase general OS X performance by using significantly more RAM by taking advantage of 64-bit extensions?

[SemjaZa]

So when are we going to notice this 64bit business? Ive never used more than 4gb of ram with one application addressing it all... are there sum magic instructions that are 64bit that willl significantly better the whole experience of using osx? or is this impressing us with bits and bytes?

 

I really doubt this will make a difference except for those with enormous ammounts of memory.

[Synaesthesia]

@ Bofors, if you are not interested in apps that use more than 1gb RAM, like you say, you won't notice much difference going above 2gb for general usage: it's pretty much the sweet spot.

 

However if you use intensive programs, especially 64-bit applications with large datasets (eg.huge photos, or video), you will see a big difference.

[CLiDE FTW!!1]

But correct me if I'm wrong. Snow leopard will support PPC as well, which wouldn't make it a true 64-bit OS?

 

ding ding ding ?

[bofors]

AppleInsider has post a four part series on Snow Leopard and the 64-bit queston:

 

http://www.appleinsider.com/topics/Road_to_Snow_Leopard.html

[MacMeGosh]

thanks... answered some questions on that one. ;-p

[MithrilFox]

As far As I know Mac os leopard is not Fully 64 bit....

But the 4 gig issue is not related to 32 bit or 64 bit... well from what I've read...

If you want to go higher than 64 gig you will need an 64 bit os...

 

Oh and since service pack1, vista 32bit has no problems with 4 gig or higher..

 

and thats not with any memory holes.... ETC!!!

 

Unfortunately that is not true about Windows (XP or Vista). It can only address and use up to 3.5GB of that. This is a known and well-recognized limitation of Windows XP/Vista 32-bit.

 

Leopard, on the other hand, can address far more. I currently have installed and running 8GB in my Leopard system, and it can fully access all of it. 8GB in a Windows XP/Vista 32-bit system will still only use 3.5GB.

 

So when are we going to notice this 64bit business? Ive never used more than 4gb of ram with one application addressing it all... are there sum magic instructions that are 64bit that willl significantly better the whole experience of using osx? or is this impressing us with bits and bytes?

 

I really doubt this will make a difference except for those with enormous ammounts of memory.

 

In other words, for people who use their Macs to work with extremely large data such as HD video, large photos, and high quality music?

 

As in... a significant portion of Mac users, considering that they make up quite a lot of the user-base. If you find a Mac user here, there's a pretty fair chance he or she uses FCS, Logic Pro, Aperture, or one of the design suite applications (Photoshop, Illustrator, etc).

[Andy Vandijck]

AFAIK Leopard kernel boots up standardly in 32-bit mode.

It enables EM64T as a kind of extension (if possible with CPU...).

Snow Leopard on the other hand has an mach_kernel Universal Binary which also contains x86_64...

So from the boot up it is fully 64-bit...

More info on this:

http://en.wikipedia.org/wiki/Mac_OS_X_v10.6

[DomozitoLK]

Leopard, on the other hand, can address far more. I currently have installed and running 8GB in my Leopard system, and it can fully access all of it. 8GB in a Windows XP/Vista 32-bit system will still only use 3.5GB.

 

I wish my Leopard install would be able to use all 8GB I have. I installed 8GB and it wouldn't boot all the way to the desktop...just blue screen with no icons or cursor. Removed a stick of DDR2 and it would boot to the desktop with 6GB installed. About this Mac only recognized 4GB, but System profiler identified all 3-sticks (6GB). Apps like console, software update and the installer app would launch and quickly crash. Removing another stick (4GB total) would give me a more stable system with all apps functioning as they should.

 

I guess it's an issue with AMD processors and 64-bit addressing under Leopard (or lack there of).

[Konami®]

I wish my Leopard install would be able to use all 8GB I have. I installed 8GB and it wouldn't boot all the way to the desktop...just blue screen with no icons or cursor. Removed a stick of DDR2 and it would boot to the desktop with 6GB installed. About this Mac only recognized 4GB, but System profiler identified all 3-sticks (6GB). Apps like console, software update and the installer app would launch and quickly crash. Removing another stick (4GB total) would give me a more stable system with all apps functioning as they should.

 

I guess it's an issue with AMD processors and 64-bit addressing under Leopard (or lack there of).

 

Perhaps your motherboard only support 4GB or the BIOS is configured to support only 4GB.

[AppleTalk]

If it's 32 bit why can it address over 4 gigs of ram?

 

valid point.

 

Last I read was that portions of the software/utilities included in leopard have not been fully ported to 64bit. but the core kernel I think is or else how can it address more than 3 gb ram...

 

I guess everyone forgot Steve Jobs demonstration of a 4gb photo running in 32bit vs 64bit app in OSX at macworld 2007 and difference in rendering speeds...unless it was the reality distortion field messing with my mind..

 

http://www.macworld.com/article/58339/2007/06/livekeynote.html

 

“Number four,” said Jobs. “Leopard is 64 bit from top to bottom.” This is the first time that 64-bit will be mainstream in the computer world, he said — not only does mean Leopard’s Unix underpinnings will be 64-bit, but so will Cocoa.

 

“One version of Leopard runs 32-bit and 64-bit apps side by side,” explained Jobs. “If you write a 64-bit app, you can guarantee that it will run on every copy of Leopard out there.”

 

To demonstrate the capability, Jobs loaded a giant photograph — 4GB in size — into a demo application that showed CPU and disk access. One version ran in 32-bit mode, the other in 64-bit mode. Running filters on both systems, the 32-bit version took 81 seconds to complete the tasks, hammering the hard disk in the process. The 64-bit version was able to load everything into memory, and finished in 28.48 seconds.

 

the other question now is....does the apps come in 2 separate installers like windows for x86 and x64 ? Most 3rd party vendor software don't state whether they run in 64 bit mode or not...which I think alot them haven't ported over to 64bit yet... just wondering.

[Ranguvar]

You can address more than 4GiB of RAM if you use PAE: http://en.wikipedia.org/wiki/Physical_Address_Extension

 

For the most part, there is no real benefit to 64-bit CPUs and apps. Only the following...

 

- PAE comes at a very slight performance loss.

- If you have an AMD64 (I call it this because it's the real name, Intel's EM64T was made to be compatible with AMD64) CPU, they can assume you have features like SSE/SSE2/etc, so they can compile in that ASM. But as we know, Apple is already able to assume all recent Macs have an SSE3 processor.

- More registers. This helps some, but I wouldn't give even a 10% across the board, much less and maybe 10% in some areas (like x264).

- There are some other benefits, but this is more being _able_ to do stuff than do stuff _faster_.

 

Overall, I say Apple's claimed advantages of 64-bit processing are hokey at best. Whether Snow Leopard has a real 64-bit kernel, I don't know. It's not like it would be terribly hard to make it such. Is that what you mean by 'OS'? Would a 64-bit kernel with everything else 32-bit count as a 64-bit OS?

[Nheru]

I know for sure that 32-bit Windows will NOT address (read "use") >3.x Gb. (It's somewhere about 3.2-3.5 Gb depending on how you measure it) From what I understand there has been a limit of 2Gb of addressed space being available to any single application, however that has been fixed through updates and service packs. Also the service packs have served to change how the memory is reported, so if you have 4gb installed, it will "recognize" it all, but it will not address (use) it all.

Note the "Physical memory available to Windows"

 

I understand my install of Leo is kinda jacked up as it's modified to run on my AMD, but it doesn't seem there should be much difficulty running the 64-bit code as AMD is the originator of the x86-64 instructions (for once, Intel had to adopt a standard they didn't create). Every item in my "Activity Monitor" shows it's kind as "Intel" (not "Intel 64") but completely recognizing all 4gb of memory. Does that mean my Leo is running the 64-bit extension to address it?

 

The Kernel is a true 32/64bit hybrid. This is excellent as the drivers from panther/jaguar days still work.Just run the included Chess program and fire up Activity Monitor and look for Chess. It will show up as Intel 64 bit if you have a 64 bit capable processor.

I tried that but it still showed up as just "Intel", not "Intel 64"

[riws]

I know for sure that 32-bit Windows will NOT address (read "use") >3.x Gb. (It's somewhere about 3.2-3.5 Gb depending on how you measure it) From what I understand there has been a limit of 2Gb of addressed space being available to any single application, however that has been fixed through updates and service packs. Also the service packs have served to change how the memory is reported, so if you have 4gb installed, it will "recognize" it all, but it will not address (use) it all.

Note the "Physical memory available to Windows"

 

I understand my install of Leo is kinda jacked up as it's modified to run on my AMD, but it doesn't seem there should be much difficulty running the 64-bit code as AMD is the originator of the x86-64 instructions (for once, Intel had to adopt a standard they didn't create). Every item in my "Activity Monitor" shows it's kind as "Intel" (not "Intel 64") but completely recognizing all 4gb of memory. Does that mean my Leo is running the 64-bit extension to address it?

 

 

I tried that but it still showed up as just "Intel", not "Intel 64"

PAE does the memory job for 4GB. You are still 32bit world. AMD's AMD64 and Intel's EM64T are compatible with each other, but not the same 100%, this is with all CPU instruction sets. And your AMD lacks of SSSE3, witch is the main deal here between AMD and Intel 64bit way in Apple's mind.

[Superhai]

If you want to be very technical for any OS and PAE, it works with memory up to 64GB. But there is an issue with page tables when using that amount of memory, they have to be in the 32 bit area together with the kernel, and for 64GB I would guess the paging table are around 1.5GB leaving not much left for the kernel. Also physical address space is still 32 bit and for many kind of hw that is required.

 

More registers may give quiet good boost, but it means it must be used as well, it is no help if you don't recompile the app. I see many knows this, but few knows why and therefore put up wild guesstimates of the performance increase. Anyway registers are storage areas inside the CPU, opposed to in memory where you will find the stack and other memory addresses. Of course if you are lucky you have the memory you want to access in the cpu cache. Memory access must go via the FSB to the memory, you might know your FSB frequency and your CPU frequency, and see the discrepancy. Registers are readily available and do not need any memory transfer, and cache as well are much much faster than memory access.

 

On the flip-side the cache needs more space in 64 bit operation due to bigger datatypes and 64 bit alignment. So chances for cache misses are higher.

[Nheru]

PAE does the memory job for 4GB. You are still 32bit world. AMD's AMD64 and Intel's EM64T are compatible with each other, but not the same 100%, this is with all CPU instruction sets. And your AMD lacks of SSSE3, witch is the main deal here between AMD and Intel 64bit way in Apple's mind.

Actually the chip in my Hack is an AMD Athlon X2 6000+. It's the 125w version and it does have the SSE3. (I linked to Wikipedia as it was quicker and easier than booting to Windows to grab a screenshot with CPU-Z)

[eject]

Actually the chip in my Hack is an AMD Athlon X2 6000+. It's the 125w version and it does have the SSE3. (I linked to Wikipedia as it was quicker and easier than booting to Windows to grab a screenshot with CPU-Z)

no, it doesn't have it, ssse3 is no missprint of sse3

 

http://en.wikipedia.org/wiki/SSSE3

[whaase]

Ok, old thread I know. But I'm wondering now, if SL it a true full 64 bit os, does it run all 32 bit apps?

[Ranguvar]

If it were, yes it would.

64-bit operating systems can run 32-bit apps just fine. The problem is running 32-bit apps that require certain libraries, because those libs must also be available in 32-bit form, but MacOS, Windows, and most GNU/Linux distros handle that gracefully.