[Gavin]

OK, so leopard has "full 64-bit native support for the underlying OS as well as Cocoa and Carbon."

I'm assuming that means there is still plenty of code that is not 64Bit native.

What parts have been left behind for later? Drivers of course.

Does it mater? Is there a real downside to leaving random bits and pieces in 32bit mode for a while, or is the goal of "totally 64 bit native" just for buzzword compliancy and bragging rights?

If Carbon API is 64 bit does it follow that carbon aps get 64 bit for free or is there some coding involved? Just a recompile?

Will this be an issue for plug in modules? Like photoshop plug-ins, or audio units (or whatever they are called)?
If we are running a 64 bit native photoshop (a future version of course) will we have to wait for our favorite plug-ins to be updated before we can really get to work?

[jamil5454]

Since the 64-bit processors Apple users can seamlessly switch between (and use) 32-bit and 64-bit simultaneously, I see no real reason to waste resources upgrading all code to 64-bit if it doesn't provide a noticible benefit.

[Big Mac]

Who said Intel processors can seamlessly switch between the modes?

[TETENAL]

Who said there is code that won't be available as 64 bit?

[Chuckit]

Originally Posted by Gavin

Does it mater? Is there a real downside to leaving random bits and pieces in 32bit mode for a while, or is the goal of "totally 64 bit native" just for buzzword compliancy and bragging rights?

If Carbon API is 64 bit does it follow that carbon aps get 64 bit for free or is there some coding involved? Just a recompile?

The primary benefit of a 64-bit processor is that you can address huge amounts of memory. Previously, it had only been possible to do this in plain Unix programs that didn't depend on any of the application frameworks. Now Carbon and Cocoa apps will be able to use all of the available memory.

[Gavin]

Originally Posted by TETENAL

Who said there is code that won't be available as 64 bit?

It is implied by the fact that they are not saying "It's all there" but rather singling out specific bits, core elements and APIs, etc.

I think we all have enough marketing savvy to recognize spin when we see it.

[Gavin]

OK, so how granular is the mode switching? The whole application? Can I run a 32 bit pliug-in in a 64 bit application , or vice versa?

I know windows 64 has some problems with compatibility (all or nothing so you can't get a driver for your printer, etc.) but I'm assuming that's thier issue and not a constraint of the new processor.

[Art Vandelay]

They said in the keynote that it's 64-bit top to bottom several times. Also the 64-bit page on the Leopard sneak peek site mentions that "Now Cocoa and Carbon application frameworks, as well as graphics, scripting, and the rest of the system are all 64-bit...the entire operating system is 64-bit."

[alex_kac]

Actually on x86 there is a HUGE benefit to going full 64-bit. 64-bit mode offers tons more registers and many other actual architectural improvements. As such on x86 - unlike most 64-bit CPUs - actually offers about 20-30% speed improvements since the compilers can use those extra registers.

[mduell]

Originally Posted by alex_kac

Actually on x86 there is a HUGE benefit to going full 64-bit. 64-bit mode offers tons more registers and many other actual architectural improvements. As such on x86 - unlike most 64-bit CPUs - actually offers about 20-30% speed improvements since the compilers can use those extra registers.

Where by "tons more" you mean "another 8" and the "20-30% speed improvements" are not usually due to the increased number of registers and are only seen in the few apps that can take significant advantage of 64-bit data types.

[Catfish_Man]

There are more reasons than one might at first expect for *not* going 64 bit (as an application developer). Unfortunately, they're all under NDA for now.

[Chuckit]

Are you under NDA?