AMD64 (also variously referred to by
AMD in their literature and documentation as “AMD 64-bit Technology” and “AMD x86-64 Architecture”) was created as an alternative to the radically different
IA-64 architecture designed by
Intel and
Hewlett-Packard, which was
backward-incompatible with
IA-32, the 32-bit version of the
x86 architecture. AMD originally announced AMD64 in 1999
[14] with a full specification available in August 2000.
[15] As AMD was never invited to be a contributing party for the IA-64 architecture and any kind of licensing seemed unlikely, the AMD64 architecture was positioned by AMD from the beginning as an evolutionary way to add
64-bit computing capabilities to the existing x86 architecture while supporting legacy 32-bit x86
code, as opposed to Intel's approach of creating an entirely new, completely x86-incompatible 64-bit architecture with IA-64.
The first AMD64-based processor, the
Opteron, was released in April 2003.