For Further Research
The official AMD Sempron website is available at http://www.amd.com/us-en/Processors/ProductInformation/0,,30_118_11541,00.html
The AMD Sempron Model 8 Data Sheet (requires free Adobe Reader from http://www.adobe.com) can be downloaded from http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/31693.pdf. Compare it to the Athlon XP Model 8 Data Sheet, available at http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/25175.pdf.
The AMD Sempron Model 10 Data Sheet can be downloaded from http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/31994.pdf. Compare it to the Athlon XP Model 10 Data Sheet, available from http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/27375.pdf.
Tom's Hardware provides a detailed core comparison of the Sempron Model 8 versus the Athlon XP Barton as part of its coverage of the Sempron. See it at http://www6.tomshardware.com/cpu/20040728/index.html.
The Tech Report compares the 2800+ and 3100+ versions of the Sempron to the new Intel Celeron D processors at http://tech-report.com/reviews/2004q3/sempron/index.x?pg=1
Anandtech compares the 2800+ and 3100+ Semprons to a gaggle of Intel and AMD processors old and new at http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2139&p=1