. AMD Athlon XP processor family is the successor to the Athlon CPU family. There were a few core revisions in the Athlon XP family:
Palomino - the first core used in Athlon XP processors. This core included full set of SSE instructions, added a data prefetch mechanism and increased the size of the Translation Look-aside Buffer. Athlon XP Palomino CPUs had 266 MHz bus speed, and were manufactured using 0.18 micron technology.
Thoroughbred - this core had smaller die size due to switching to 0.13 micron manufacturing process. Athlon XP CPUs based on this core had lower core voltage and lower power dissipation than the Palomino processors. Bus speed of some Thoroughbred processors was increased to 333 MHz.
Barton - this core doubled L2 cache size to 512 KB. Bus speed of the Athlon XP Barton processors was increased to 400 MHz. Like the Thoroughbred processors, all Barton microprocessors were manufactured using 0.13 micron technology.
Thorton - this core is essentially the same as the Barton core with L2 cache size slashed in half - from 512 Kb to 256 Kb.
Beginning from the Athlon XP CPU family AMD started to use rated speed instead of actual processor speed.
THe Athlon MP is basically an XP that is certified for a dual proccesor sytem.