This Chinese site (the same one that shared the confidential ATI slides with us last week (see this news story) shared with us some info, which allows us to derive a new formula and to calculate the rating of Athlon XP processors based on 0.13micron Barton core (it is none other but a Thoroughbred with 512KB L2 cache, which will be manufactured by UMC only and the mass production of which is planned for Q4 2002). Here is this formula:

Rating =3 x Frequency/2 + 100

The reverse formula is also very easy to derive, as you may see:

Frequency =2 x Rating/3 - 66

These formulas are very similar to those used to calculate the rating of Athlon XP processors on Thoroughbred and Palomino core (Rating = 3 x Frequency/2 – 500 and Frequency = 2 x Rating/3 +333, see this news story). Now you will understand why:

Frequency	Palomino (0.18micron, L2=256KB)	Thoroughbred (0.13micron, L2=256KB)	Barton (0.13micron, L2=512KB)
1.33GHz	Athlon XP 1500+	-	-
1.4GHz	Athlon XP 1600+	-	-
1.46GHz	Athlon XP 1700+	Athlon XP 1700+	-
1.53GHz	Athlon XP 1800+	Athlon XP 1800+	-
1.6GHz	Athlon XP 1900+	Athlon XP 1900+	-
1.67GHz	Athlon XP 2000+	Athlon XP 2000+	Athlon XP 2600+
1.73GHz	Athlon XP 2100+	Athlon XP 2100+	Athlon XP 2700+
1.8GHz	Athlon XP 2200+	Athlon XP 2200+	Athlon XP 2800+
1.87GHz	-	Athlon XP 2300+	Athlon XP 2900+
1.93GHz	-	Athlon XP 2400+	Athlon XP 3000+
2GHz	-	Athlon XP 2500+	Athlon XP 3100+

As you see, the doubling of the L2 cache size provides a 600+ increase of the AMD rating. So, the rating of Athlon XP (Barton) can be obtained from Athlon XP (Palomino or Thoroughbred) working at the same frequency by simply adding these "pluses" to the rating of the latter.