I just stumbled across an interesting article that details why support for PPC was dropped from Snow Leopard.
Quote:
PowerPC is being dropped from Snow Leopard because there is no similar performance advantage with the PowerPC architecture in going 64-bit as there is in moving from x86 to x64. X64/AMD64 offers twice as many general purpose registers as x86, and that's where virtually all of the performance boost derives. The performance gain usually offsets any performance loss associated with using larger data items by ~15% but not uncommonly by as much as 25%.
Not the case with PowerPC. The number of general purpose registers is unchanged between 32-bit and 64-bit PPC, so applications are left with the performance loss of using larger datums in 64-bit mode. As a result, PowerPC apps typically run a little slower in 64-bit mode than in 32-bit mode.
|
Myths of Snow Leopard 2: 32-bit Support — RoughlyDrafted Magazine