The Athlon 64 is a ninth-generation, AMD64-architecture microprocessor produced by Advanced Micro Devices (AMD), released on September 23, 2003. It is the third processor to bear the name Athlon, and the immediate successor to the Athlon XP. The Athlon 64 was the second processor to implement the AMD64 architecture and the first 64-bit processor targeted at the average consumer. Variants of the Athlon 64 have been produced for Socket 754, Socket 939, Socket 940, and Socket AM2. It was AMD's primary consumer CPU, and primarily competed with Intel's Pentium 4, especially the Prescott and Cedar Mill core revisions.
AMD Athlon 64 3200+ (2.0 GHz) Clawhammer, Socket 754. It is one of the first x86-64 processors available to the general consumer market.
Model MT-34
MT-34 (bottom)
Image: AMD Athlon 64 FX
x86-64 is a 64-bit version of the x86 instruction set, first announced in 1999. It introduced two new modes of operation, 64-bit mode and compatibility mode, along with a new 4-level paging mode.
AMD Opteron, the first CPU to introduce the x86-64 extensions in April 2003
The five-volume set of the x86-64 Architecture Programmer's Manual, as published and distributed by AMD in 2002