Originally Posted by fourthletter
Pretty much everything works in 64 Bit windows it just lacks 64 bit drivers for old equipment, which is considerably older than Power G5s.
I use Windows Server 2003 for Active Directory. I can't use Microsoft's own Group Policy Management Tool because they don't even provide a 64-bit version! Most of the applications I've come across very rarely offer 64-bit versions. Most of my applications get relegated to the mandatorily segregated folder "Program Files x86". My first crude implementation of an iTunes media server required me to hack the Vista x64 version of iTunes to get it to run on my platform. Needless to say, it wasn't very stable.
While the availability of 64-bit drivers for newer, business class machines is typically better than the typical consumer-class machines, it still can not be expected. My recent model (last year) consumer Canon inkjet photo printer does not have 64-bit drivers available because the demand wasn't high enough in a consumer world of almost entirely 32-bit default Windows installations. This required me to use generic print drivers for sharing it to my 32-bit and 64-bit clients through Active Directory. This is because there is a limitation in Server 2003 where it is possible to serve both 32-bit and 64-bit drivers to clients for the same printer, but they have to be drivers registered under the same manufacturer ID. Though, my business class Canon Laser printer provided 64-bit drivers and all is well. I remember considering exchanging my 64-bit version of Server for a 32-bit one because of all of these problems, but I just ended up relegating it to nothing more than AD and all resources are shared via Leopard Server and Samba.
Originally Posted by fourthletter
But happily forget that Steve Jobs told us first that Tiger was a 64 bit OS then Leopard and now finally we have Snow Leopard which is definitely a 64Bit OS, umm apart from the 32Bit Kernel that will run on most non-pro Macs.
Jesus the 64bit move has been long and hard and both sides are doing very little to make it simple.
While the kernel, extensions, drivers, and UI frameworks (Carbon & Cocoa) were still 32-bit, Tiger brought 64-bit unix processes (not kernel) which enabled still 32-bit GUI applications to spin off intense, number-crunching 64-bit processes that could report back the results. The Universal Binary application strategy was born. Both 32-bit and 64-bit boot processes were provided to enable either architecture to be supported on the same OS! These design decisions enabled for a smooth transition to 64-bit as opposed to Microsoft's all-or-nothing approach, which explains the poor adoption of 64-bit Windows and their still-existing 32-bit limitation of 4GB of addressable memory.
As opposed to Windows, where you either get x86 or x64, Apple enabled a fail-safe of being able to switch between the two different kernels. They are now using this to give the manufacturer's one last change to complete their 64-bit kexts. As Apple was nearing completion of Snow Leopard, it put out a call to all device manufacturer's to make sure that their kexts were ready for 64-bit. Knowing that device manufacturer's very often experience delays in completing projects on time, they are giving them one last chance. They decided to unexpectedly release Snow Leopard as defaulting to a 32-bit kernel on most machines. All of the architecture is complete and ready for Apple to flip the switch. Excellent transition IMO! [source: AppleInsider]