[citation][nom]daneren2005[/nom]64 bit is an improvement because there are data types being used that are larger than 32 bits. The largest common data type is 64 bit though, so I really don't see 128 bit providing nearly as big of a performance increase.[/citation]
Read the thread. Long datatypes have been crunched in 64 and 128 bit long segments in "32-bit" cpus for a rather long time. Not only that, but we also crunch multiple shorter datatypes, 8, 16, 32, 64, in 128-bit long fields, in 128-bit long vector-registers and 128-bit wide hardware units. And we even do it in multiple parallel pipes as well. And soon, some cpus might feature 512-bit long vector registers. Those cpus will still be "64-bit"
When we today talk about 16-, 32- and 64-bit computing, OS or CPUs, it has nothing to do with width of computing, width of registers or width of datatypes. Width of computing increase all the time, with each generation of CPUs and greater transistor counts. That is what all this SSE, SIMD, MMX -things (which you may have heard about) is all about.
Articles, dictionaries or other books that tell you 16/32/64 is about the length of registers, are simply WRONG.
The bitness, of a CPU, OS or software, is about how long the adress, which refers to the virtual adress of the data, is in the machinecode instructions. This adress is used by the OS and CPU to map to a hardware location, usually a physical adress, which in a 16-bit computer is always longer than the virtual adress, in a 32-bit is typically longer, and in a 64-bit is always shorter.
And this "128-bit" Windows nonsense is either total bogus or a severe misunderstanding. OS'es will remain 64-bit for decades.