AMD's Athlon XP is based on the revamped Athlon Thunderbird core (codename Palomino) using copper interconnects and built on the .18 micron process. The Athlon XP also uses a much better organic packaging, rather than the ceramic/chisel of the previous versions of the Athlon and Duron.
Internally, the Athlon XP has improved 3DNow! Professional which adds Intel's SSE to the AMD arsenal. AMD has also added Data Prefetch capability to the Athlon XP to help speed up data transfers through the CPU itself. There is also 128K of L1 cache with an additional 256K of L2 cache running at full core speed. The Athlon XP also runs with a 1.75V core voltage on a 133 MHz (266 MHz effective DDR) front-side bus. AMD has also made some architectural improvements that help decrease core heat, and allow the Athlon XP to run cooler at higher clock speeds.
Currently there are seven different versions of the Athlon XP ranging from the 1.33 GHz Athlon XP 1500+ all the way up to the 1.73 GHz Athlon XP 2100+. Below you will find a list of Athlon XP processors and their respective clock speeds and multipliers.
Athlon XP Model
Core Speed
Multiplier
Athlon XP 2100+
1.73 GHz (266)
13.0x
Athlon XP 2000+
1.67 GHz (266)
12.5x
Athlon XP 1900+
1.60 GHz (266)
12.0x
Athlon XP 1800+
1.53 GHz (266)
11.5x
Athlon XP 1700+
1.47 GHz (266)
11.0x
Athlon XP 1600+
1.40 GHz (266)
10.5x
Athlon XP 1500+
1.33 GHz (266)
10.0x
This list can give you a very basic view of the range of available clock speeds, thereby allowing you to set some overclocking targets. With the Athlon XP 2100+, AMD seems to be reaching the limits of the current core, at least for standard air-cooling. Some Athlon XP processors have been known to reach up to 2.0 to 2.2 GHz with various water and/or Peltier based cooling hardware, as well as using extreme voltage (upwards of 2V). For this article, we are limiting ourselves to the standard CPU cooling devices. The upcoming Thoroughbred version of the Athlon XP should offer higher speeds, as AMD moves to the lower-voltage, 0.13 micron process.