Xp processor uses the same chip core, code named Palomino which can be found in Athlon 4 notebook chips. It is supposed to use about 20% less power then the original Athlons and has 3DNow professional which adds 52 new 3D and multimedia instructions which makes it compatible with Intels SSE instructions. They are definatly a much improved processor from the K6, and the only difference that I have noticed in my xp1800+ to the P4 1.7gig is that it is alot smoother and faster in gaming....but there is no difference between the two in speed to information to waiting applications. Yes the AMD is alot cheaper, but I havent given up on Intel upping the anti, performance wise