AMD64
The AMD64 is a 64-bit processor architecture invented by AMD. It is a superset of the x86 architecture, which it natively supports.
Architecture Overview
TODO: write about the AMD64 architecture. New instructions, capabilities, register sizes, etc.
Operating Modes
TODO: Write about the operating modes, and the capabilities of each.
AMD64 Market Analysis
AMD64 represents a break with AMD's past behavior of following Intel's standards, but follows Intel's earlier behavior of extending the x86 architecture, from the 16-bit 8086 to the 32-bit 80386 and beyond, without ever removing backwards compatibility.
The AMD64 architecture extends the 32-bit x86 architecture (IA-32) by adding 64-bit registers, with full 32-bit and 16-bit compatibility modes for earlier software. Even the 64-bit mode is largely backward-compatible, allowing existing tools targeting x86 (eg. compilers) to be retargeted to AMD64 with minimal effort. The AMD64 architecture also features the NX bit.
Implementations
The following processors implement the AMD64 architecture:
- AMD Athlon 64
- AMD Opteron
- Intel Xeon (some models)
- Intel Pentium 4 (some models)
See also
- NX
- EM64T (Intel's implementation of the AMD64 architecture)
