Comment Not really about performance (Score 2, Insightful) 69
The move from 32 to 64 bits isn't so much about performance as it is about ...size, I guess. The ability to hold huge databases and datasets in a flatly addressable space. The ability to do maths with larger and/or more accurate numbers. That kind of thing.
As I recall, a 286 was slightly faster than a 386 at the same clockspeed. The 486 was the first x86 that was actually designed to go fast. The big deal about the 386 was that it did memory management properly, and had the multitasking abilities, and to do that it needed a large addressable flat memory space (hence 32-bit pointers). The 32-bit registers were that size mainly so they could hold pointers and offsets and things. (Yes, I'm simplifying, I know.)
64-bit CPUs will be faster at a few things, like copying memory and crunching RC5, but most performance benefits in future CPUs will have nothing to do with word-size (clock speeds, cache sizes, clever pipelines, etc.).
As I recall, a 286 was slightly faster than a 386 at the same clockspeed. The 486 was the first x86 that was actually designed to go fast. The big deal about the 386 was that it did memory management properly, and had the multitasking abilities, and to do that it needed a large addressable flat memory space (hence 32-bit pointers). The 32-bit registers were that size mainly so they could hold pointers and offsets and things. (Yes, I'm simplifying, I know.)
64-bit CPUs will be faster at a few things, like copying memory and crunching RC5, but most performance benefits in future CPUs will have nothing to do with word-size (clock speeds, cache sizes, clever pipelines, etc.).
