First and foremost, the name 'AthlonXP' is not just following the current trend to call everything after Microsoft's new operating system WindowsXP (like e.g. NVIDIA's new originally named driver set 'DetonatorXP'), but the 'XP' that is supposed to hype the new 'experience' you might have with WindowsXP, is supposed to suggest the 'extreme performance' of AthlonXP.
New Features
AthlonXP does indeed offer 3-7% more performance per clock than previous desktop-Athlons based on the "Thunderbird"-core, because it is based on the new "Palomino"-core that we already know from AMD's multi-processor offering AthlonMP and the Mobile Athlon4 processors.
I'll list Palomino's added features over Thunderbird once more:
• New design to reduce power consumption over Thunderbird core by 20%
• Implementation of the full Intel SSE instruction set. The SSE processor flag is set (if the motherboard BIOS supports Palomino) so that software can recognize AthlonMP as a SSE-capable processor. AMD calls its SSE-implementation '3Dnow! Professional'.
• Hardware auto data pre-fetching unit
• L1 Data TLB (Translation Look-Aside Buffer) was increased from 32 to 40 entries, the architecture of the data and instruction L1 and L2 TLBs was made exclusive and TLB-entries can be written speculatively.
• Implementation of a thermal diode to monitor processor temperature
AthlonXP comes in a new packaging, which is based on the same material as found in Intel's Pentium III, Celeron and Pentium 4 processors. The only difference is that the material used with AthlonXP is brown, while the Intel processors are green. The new material is supposed to have better thermal behavior and more elasticity than the previously used ceramic. Besides this important feature, the new organic material is also lighter and cheaper than the previous packaging material
