64 bit Programs - What and When?

Nothing in 10.3 is 64-bit. In 10.4, the OS will have some 64-bit memory management, but as of yet, no apps are 64-bit.

 

Neither Adobe Creative Suite 1 or 2 are 64bit. One way to tell is how much memory the application can address. If it's limited to 3.5 GB or less, then it's a 32bit application.

In truth, not all applications will benefit from going 64bit, so you can expect that at least some applications will be 32bit for the time being. And as for the applications that can benefit from being 64 bit, you'll start to see them coming out over the next year or two. Remember that a 64bit application has a limited audience right now, so there has to be enough reason for them to release a 64bit version.

And you will most likely see the "Pro" applications go 64bit before other applications. (Final Cut Pro, DVD Studio Pro, Photoshop CS#, Logic Pro, etc.)

 

Panther has 64-bit, G5 optimized math libraries. There's also a G5 Photoshop plugin that exploits 64-bit G5 instructions. Tiger adds 64-bit memory addressing for command line apps (not the GUI frameworks).

 

The Tiger 64 bit implementation makes it a little difficult for apps to go 64 bit especially existing apps. Neither Cocoa or Carbon are going 64 bit so the GUI of all apps has to stay in 32 bit land. This is actually a good thing as 64 bit app are almost always slower (as long as nothing else changes) than 32 bit version as you need to load bigger pointers etc for every instruction. The reason that x86 64 bit processors are faster in 64 bit mode is because they added a load of general purpose registers in 64 bit mode (although they still end up with less than PPC), whereas PPC does not change anything to go to 64 bit mode.

To make a 64 bit app you need to put all the 64 bit processing in a command line app and have the GUI communicate via pipes or shared memory. This will be a pain in the ass for existing apps as they are mostly not designed in this way!