In 2002 the Athlon XP-M (Mobile Athlon XP) replaced the Mobile Athlon 4 using the newer Thoroughbred core, with Barton cores for full-size notebooks.
The Athlon XP-M (mobile Athlon XP) was released in 2002 to replace the older Mobile Athlon 4. This new processor used the Thoroughbred core design for desktop computers, while notebooks received the Barton core variant.