FX-51

Background

The Athlon 64 was originally codenamed ClawHammer by AMD, and was referred to as such internally and in press releases. The first Athlon 64 FX was based on the first Opteron core, SledgeHammer. Both cores, produced on a 130 nanometer process, were first introduced on September 23, 2003. The models first available were the FX-51, fitting Socket 940, and the 3200+, fitting Socket 754. Like the Opteron, on which it was based, the Athlon FX-51 required buffered random-access memory (RAM), increasing the final cost of an upgrade. The week of the Athlon 64's launch, Intel released the Pentium 4 Extreme Edition, a CPU designed to compete with the Athlon 64 FX. The Extreme Edition was widely considered a marketing ploy to draw publicity away from AMD, and was quickly nicknamed among some circles the "Emergency Edition". Despite a very strong demand for the chip, AMD experienced early manufacturing difficulties that made it difficult to deliver Athlon 64s in quantity. In the early months of the Athlon 64 lifespan, AMD could only produce 100,000 chips per month. However, it was very competitive in terms of performance to the Pentium 4, with PC World calling it the "fastest yet". The Athlon FX-51 was also outperforming the Pentium 4 3.2C in Quake III Arena and Unreal Tournament 2003 benchmark, according to Maximum PC. "Newcastle" was released soon after ClawHammer, with half the Level 2 cache.