Introduction

AMD’s seventh generation Athlon processor has served the company well for the past four years. In fact, the success of Athlon saved AMD from the brink of extinction.

In more recent times however, the architecture has begun to show signs of age. While Intel has moved at a steady pace incorporating new performance-enhancing features into the Pentium 4, they’ve also been cranking up the Pentium 4’s clock speed. Increments of 133MHz and more recently, 200MHz, have been achieved. Meanwhile, AMD has been struggling to get considerably past 2GHz.

The end result is that Intel’s processor lineup has been winning an increasing number of benchmarks, including applications that have traditionally favored AMD’s Athlon. AMD has extended the life of its Athlon XP processor by incorporating more cache with Barton, and increasing the processor’s bus speed to 400MHz, but these were only stopgap measures, AMD needed a new architecture and they knew it. Their answer lie in K8, also known as the Hammer family. Not only would Hammer bring with it a new micro-architecture to fight Pentium 4, it would also introduce the world to AMD’s vision of 64-bit computing. Unfortunately for AMD, it just wasn’t ready for release.

Finally, after considerable delays and months of speculation, AMD’s first 64-bit desktop processor is here: the Athlon 64 family. AMD is working hard to make up for lost time too, as they’re bringing two products to market, the Athlon 64 and the Athlon 64 FX.

940 pins down there

The system configured

AMD's Athlon 64 FX-51 chip

At the extreme high-end of the desktop PC space, AMD offers the Athlon 64 FX. This is AMD’s new flagship processor. Just below it is the Athlon 64, this is AMD’s latest offering for the mainstream consumer. Both processors are based on the same basic core, and while the initial Athlon 64 launches with the 3200+ rating, AMD claims that it performs faster than the Athlon XP 3200+. We’ve already gone over the micro-architecture in our Opteron 242 article, so lets quickly rehash the basics before explaining the differences between Athlon 64 and Athlon 64 FX.

Most importantly, AMD has designed the Athlon 64 processors to be outstanding performers in both 32-bit and 64-bit applications. In fact, it would probably help if you think of the Athlon 64 primarily as a 32-bit processor, as 64-bit applications are still few and far between. Just consider its 64-bit capability as an added bonus for the future.

Second, the Athlon 64 isn’t the dramatic difference in design that the Pentium 4 was over the Pentium III. Instead, AMD has tweaked the Athlon’s core for more performance per clock cycle, while at the same time tweaking the registers for 64-bit use.