Advanced Micro Devices Inc (AMD)

[chipguy]

Also, Itanium has a larger core with more transistors than P4 or Opteron at the same geometry, as I understand it.

You understand wrong. A Northwood P4 core has about
29m logic transistors. A Madison I2 core has about 20m
logic transistors, probably less than 14m if you remove
the x86 compatibility features. The P4 core is over 100
mm2. The I2 core is about 80 mm2, perhaps 65 mm2
with x86 logic removed.