The short answer is that Leopard is a mix of 32-bit and 64-bit. Tiger added 64-bit support for low-level system libraries, enabling 64-bit for non-GUI applications. Leopard added 64-bit support throughout the system frameworks, so any app can be 64-bit. Sep 30, 2017 - Apple macOS X Snow Leopard 10.6 ISO download from here and mac os.
Does Mac OS X 10.7 'Lion' boot in 32-bit mode or 64-bit mode by default? Does it run on Macs with a 32-bit EFI or just Macs with a 64-bit EFI?As first reported by the well respected hacker, the final version of OS X Lion has a Finder that only runs in 64-bit mode. However, OS X Lion does run on a number of Macs that have a 32-bit EFI but that also have a 64-bit processor. It cannot run on Macs with 32-bit processors.Also see: Macs are compatible with Mac OS X 10.7 'Lion'? Which Macs are not compatible?
Can incompatible Macs be 'hacked' or upgraded to run Mac OS X 10.7 'Lion'?How does the performance of Mac OS X 10.7 'Lion' compare to Mac OS X 10.6 'Snow Leopard' in 'real-world' tests?When Mac OS X 10.6 'Snow Leopard' was released, Apple advertised that it was streamlined and a variety of speed 'refinements' compared to earlier versions of the operating system.By contrast, for Mac OS X 10.7 'Lion,' the company advertises that it provides '250 new features' and makes no mention of performance. For that reason alone, it would be safe to assume that the operating system is certainly no faster than Snow Leopard and even might be slower. However, only 'real-world' tests can confirm or deny this assumption.In benchmark tests and application use, C Net's blog the running both Snow Leopard and Lion and 'found only minor speed variations between the two operating systems.' The blog also that 'with the exception of the application launching test it seems like there are few differences between the two operating systems' and produced this helpful video to compare boot time, file duplication, web browsing and more:Ultimately, as the benchmarks and usage tests confirm, OS X Lion is more about new features and multi-touch interaction than speed, but it remains equally quick as its predecessor for most tasks nevertheless.