K7.

This is the original Athlon from August 1999 and was manufactured using a 0.25 micron lithography process. Like the Pentium II and the Katmai Pentium III the K7 Athlon was mounted on a daughterboard which required a slot on the motherboard to house it. The reason for the daughterboard arrangement was to accomodate 512 KB of level 2 cache which comprised two chips running at half clock speed on the daughterboard. Clock speeds ranged from 500 to 700 MHz. All chips had a 100 MHz bus speed.

K75.

After only a few months of production came the K75 Athlon. This differed from the K7 in that it was manufactured using a 0.18 micron lithography process. As clock speeds rose past 750 MHz it became necessary to drop the level two cache divider to one third of CPU clock speed. This did have an impact upon performance. The K75 does have a big claim to fame in that it was the first desktop x86 CPU to run at 1 Ghz. All chips had a 100 MHz bus speed.

Thunderbird.

In many respects the Athlon only really came of age when the “Thunderbird” core was launched in June 2000. This core was very different from the K7 and K75 in that it no longer required externally mounted SRAM chips for level two cache instead relying upon 256 KB of integrated SRAM to perform this function. The Athlon “Thunderbird” was the second time AMD had integrated 256 KB level 2 cache onto a CPU core building upon valuable lessons learnt from the K6 III. As the level 2 cache was now integrated onto the CPU core, AMD could now mount the chip using a Socket design in the form of Socket A which was far cheaper than the old Slot A design. Clock speeds ranged from 700 MHz to 1.4 Ghz. Bus speeds included both 100 and 133 MHz.

Palomino.

The “Palomino” was the next major revision of the Athlon core in summer 2001. Like the “Thunderbird”, the “Palomino” was manufactured using a 0.18 micron process. Significant revisions included support for Hardware Data Prefetch and Intel’s SSE instruction set. There was also a number of enhancements to the basic Athlon design resulting in better performance per clock speed when compared to the “Thunderbird”. This was the first chip to be branded Athlon XP and ran from clock speeds of 1.33 Ghz (XP 1500+) to 1.8 Ghz (XP 2100+). All chips used a 133 Mhz bus.

Thoroughbred.

The “Thoroughbred” was launched in 2002 and was a 0.13 micron shrink of the earlier “Palomino” core. Initial versions proved troublesome and a revised “Thoroughbred A” was released. The biggest change for the “Thoroughbred” was the introduction of a 166 MHz bus speed with the x.xx Ghz chip (XP 2700+). Speeds ranged from 1.9 Ghz (XP 2200+) to 2.25 Ghz (XP 2800+) with bus speeds of 133 and 166 MHz.

Athlon XP - Intro.

Athlon XP - SSE.