PC Hardware in a Nutshell, 3rd Edition

The AMD Athlon Family

The AMD Athlon, which was originally code-named the K7 and began shipping in August 1999, was the first Intel-compatible processor from any maker that could compete on an equal footing with mainstream Intel processors of the time. First-generation Athlon processors matched or exceeded Katmai-core Pentium III processors in most respects, including (for the first time ever) floating-point performance. Intel finally had a real fight on its hands.

Although AMD represented the Athlon as the first seventh-generation processor, we regard the K7 Athlon as essentially an enhanced sixth-generation processor. Athlon has, in theory, several advantages relative to the aging Intel sixth-generation architecture, including the ability to perform nine operations per clock cycle (versus five for the Pentium III); more integer pipelines (three versus two); more floating-point pipelines (three versus one); a much larger L1 cache (128 KB versus 32 KB); more full x86 decoders (three versus one); and a faster FSB (100 MHz double-pumped to 200 MHz by transferring data on both the rising and falling edges of the clock cycle versus the single-pumped Intel 100/133 MHz bus, which transfers data only once during a clock cycle). While all that was very nice, tests showed that in practice the K7 Athlon and Pentium III were evenly matched at lower clock speeds, with the Pentium III sometimes showing a slight advantage in integer performance, and the Athlon a slight advantage in floating-point ...