PC Peripherals Is Athlon 2000 or Sempron 2500 Better?

[Scramjet]

I have two PCs, one with an AthlonXP 2000+ (166x10=1666MHz) & an ASUS A7N8X-X.
The other one has a Sempron 2500+ (200x7=1400MHz) & an ASUS K8V-X (Socket 754).
Going by PR Rating system of AMD the Sempron should be the better performer, but the Athlon shows better results when I run the SiSoft Sandra `CPU Arithmetic Benchmark`.
Both PCs are running WinXP 32-Bit. Is it that the Sempron would perform only on a 64-Bit OS or is the PR rating thing a scam?

 

[NinByChoice]

The PR ratings of the Sempron are to be compared to a Celeron, while those of the Athlon are to the Pentium. So you cant compare them directly and the AthlonXP might outperform the Sempron even if the AthlonXP is rated lower. I feel the AthlonXP will perform better too and it does .

Raghu.

 

[Scramjet]

Thanks Raghu.