G5 processors only 32bit under Tiger?

[disrupt_the_imc]

That's what i've been told. Under Tiger 64bit G5's are only utitized as 32bit. This doesn't make any gaddamn sense!

[brinxmat]

You said it. No it doesn't make any sense, however the geniuses at Apple cannot come up with a graphical interface that runs in 64-bit (the current, and all previous versions of OSX have a 32-bit Finder layer to hamper their progress). This means that the only thing that actually works faster through 64-bit computing on a Mac is non-graphical apps, which are admittedly not the top of the list of Mac-user priorities.

On the other hand, 64-bit computing is not necessarily something that increases speed per se because there are a lot of issues regarding memory management, address space and so forth. This kind of thing leads to, for example, slower start-up times for 64-bit software than 32-bit, which isn't problematic for long-running apps, but is typically a problem for software that you use on-and-off, for short periods. Additionally, the vast majority of software is still coded for 32-bit architecture (because of difficulties re-writing C/C++ to cope with 64 versus 32 bits).

On the other hand, porting of Apple code to 64-bit architecture (as long as it is Cocoa, not Carbon (i.e. C++)) is relatively simple, whereas porting C++ apps to 64-bit is difficult and often unlikely to happen. Guess whether the Finder is written in Cocoa or C++.

This latter kind of thing is why my next computer will be a bog-standard Intel/AMD box with Linux which, amusingly is 64-bit.