IA32 Architecture Family: Difference between revisions

This is slightly offtopic here, but still quite relevant, since these processors all support the entire IA32 family natively. AMD created a new processor, with 64-bit (actually 48-bit, but who notices those 16 bits?) memory addressing and 64-bit calculations, being very compatible with the old style CPU's. So compatible, that the core for 32-bit and 64-bit is essentially equal, aside from the size of calculations and the support of a few encodings that were in effect redundant. They removed a few 1-byte opcodes (about 20 in total, including all 1-byte INC and 1-byte DEC instructions) to make place for a new REX prefix. They modified it to use 16 registers instead of 8, added a load of new names, got the old software working, and optimized the 32-bit performance to unprecedented levels. These CPU's outperform the P4 at any clock speed, in almost (1/20 programs not) any calculation-intensive program. This made them very popular, but also very expensive, The cheapest nowadays is around 180 dollars, or euro's.