"Opteron is a server/workstation chip and should be compared to Xeon, Xeon MP and Itanium."
The Fan boys keep putting out Opteron vs Pentium 4 performance data and claims - and I haven't seen you object to that comparison - why are you suddenly so sensitive to the Opteron-Xeon sort of thing? What are you going to use for an argument when the 940 pin Athlon64 gets launched?
Petz - [THG] says that the Northwood "A" core is 146 mm. Again, according to THG, Opteron is 193mm. That difference is 32%, not 42%.
Intel hasn't made that old stepping for many moons now. The current die size is ~130mm2. That makes Opteron 48.5% larger. THG is clearly wrong on a lot of their facts. They even list Vcc at 1.50V.