what does PR rating mean?
Performance rating I believe.
If I read right PR is Pentium equivalent rating. Say the Athlon 1.4Ghz chip runs as fast as a P4 1.8 GHz chip. It would have a
PR 1800 rating. I could be wrong though.
There is a bit of confusion here.
The Athlon's do NOT use a PR rating. They use a Model Number rating.
PR ratings were used by Cyrix back around 1997 to denote Pentium performance. Their processors did not run as fast as Pentium chips but (according to them at least) offered comparable performance in industry benchmarks.
Cyrix chips, however, did NOT offer this level of performance and, to top it off, were buggy, hot, and unstable. Cyrix eventually went bankrupt and the entire issue left a bad taste in everyone's mouth.
The Model Rating of the AMD chips is different than the earlier PR rating in several ways.
1) AMD chips DO live up to their model rating. The '1800' section of the rating denotes that the chip performs like a T-bird 1800, while the '+' denotes that the chip is also comparable to 'other' processors at that speed.
2) Unlike the Cyrix chips, AMD is introducing model numbers as a preliminary method of shifting how computers are benchmarked. Unlike Cyrix, who introduced its method in a vacuum, AMD has formed a consortium with other tech companies to create a standard of measurement to more accurately reflect machine performance.
3) Also unlike Cyrix, AMD has been far more conservative in their method of chip marking. The AMD chips generally perform above their rating listing--not below it--at any point.
Yeah the PR rating should definitely NOT be confused with AMD's model rating. The model rating is based on performance of T-bird core vs Palomino in 30 of the industry standard benchmarks. Just let reviews of XP's speak for themselves, the 1800 could be called a 2000+ in a pentium rating.