I have heard rumors, and now I see this post from MacNN, that state that niether the User Interface of tiger, nor FCP5 will be 64 bit. What do you know about this. Here is the post:
From a presumably Apple developer on /.
"You're missing something massively important. The reason why we chose not to release 64-bit versions of the UI frameworks is that they run much slower than the 32-bit versions.
User interface code is really pretty messy when you get right down to it. You're doing a lot of abstraction, moving a lot of pointers and integers around. On exactly the same G5-based computer, a 64-bit UI is going to run considerably slower than a 32-bit UI because of cache exhaustion. Because you're using pointers that are twice as big as you need them to be, you can only fit half as many of them in the various caches that are there to speed up your computer's performance. That effectively cuts your caches in half.
So we had two choices: Either waste a ton of developer time releasing 64-bit-clean versions of the UI frameworks and then tell our developers not to use them, or just don't ship them at all.
Believe me, the Final Cut Pro and Shake teams were pissed off about this. Their expectation was that they'd be able to release 64-bit versions of their applications by NAB. But a 64-bit version of FCP with 64-bit Pro Kit is less interactive than the 32-bit version on the same hardware, for very marginal gains in actual utility. FCP is already very good at making use of up to 2 GB of RAM when dealing with hundreds of gigabytes of data on disk; adding 64-bit support would have helped few and hindered many."
"It is important to note that in the Tiger release, the support for 64-bit programming does not extend throughout the entire set of APIs available on Mac OS X. Most notably, the Cocoa and Carbon GUI application frameworks are not ready for 64-bit programming. In practical terms, this means that the "heavy lifting" of an application that needs 64-bit support can be done by a background process which communicates with a front-end 32-bit GUI process via a variety of mechanisms including IPC and shared memory."
Sounds true and makes perfect sense in the current state of the mac. Only the the iMac and PowerMac have G5 processors and they are converting code to 64-bit in logical chunks. Tiger makes a big advancement in terms of Core Image and Core Data so maybe with this huge amount of work completed they will focus on updating the GUI libraries to be 64-bit compliant as well. The GUI can call 64-bit non GUI code though... so in theory FCP or other apps could make separate "render" applications that simply pass back the data at the end of their jobs. The conclusion on the page hints at this:
"As you have seen, Mac OS X Tiger takes the next step in 64-bit computing with the ability to build certain types of applications, such as server applications, and background processes used by renderers and computational engines, as 64-bit applications. These lower-level tools can communicate with graphical front-end applications for presentation and other visually-oriented functions."