YB I think anyone will agree that P4 (and Itanium too) requres wast manufacturing resources, because it's design needs a lot of cache.
"Vast", not "wast", and with NorthWood at less than 135mm2 I think your should contrast that with the projected 185mm2 die size for Opteron. So who needs the "vast" manufacturing resources? With the Athlon64, the 256K L2 version, essentially canned because of poor performance, it would seem that Opteron is the one dependent on a very large cache to be competitive, and even still it will fall short of current, much smaller Northwood in SPEC performance if expectations hold. AMD's choice of SOI will prove to be the biggest blunder in the companies history.