AMD Athlon 64 FX (Sledgehammer, Clawhammer, San Diego) processors
Introduction: September 2003 (Sledgehammer), June 2004 (Clawhammer), June 2005 (San Diego)
The Athlon 64 was an eighth-generation, AMD64 architecture microprocessor produced by AMD, released on September 23, 2003. It was the third processor to bear the name Athlon, and the immediate successor to the Athlon XP. The second processor (after the Opteron) to implement AMD64 architecture and the first 64-bit processor targeted at the average consumer, it was AMD's primary consumer microprocessor, and competed primarily with Intel's Pentium 4, especially the "Prescott" and "Cedar Mill" core revisions. It was AMD's first K8, eighth-generation processor core for desktop and mobile computers. Despite being natively 64-bit, the AMD64 architecture was backward-compatible with 32-bit x86 instructions. Athlon 64s had been produced for Socket 754, Socket 939, Socket 940, and Socket AM2.
The Sledgehammer, Clawhammer and San Diego cores
The Athlon 64 FX was positioned as a hardware enthusiast product, marketed by AMD especially toward gamers. Unlike the standard Athlon 64, all of the Athlon 64 FX processors had their multipliers completely unlocked. The FX line was then dual-core, starting with the FX-60. The FX always had the highest clock speed of all Athlons at its release. From FX-70 onwards, the line of processors also supported dual-processor setup with NUMA, named AMD Quad FX platform.
Source: Wikipedia, the free encyclopedia.