Select this for Intel Pentium 4 chips. This includes the
Pentium 4, Pentium D, P4-based Celeron and Xeon, and
Pentium-4 M (not Pentium M) chips. This option enables compile
flags optimized for the chip, uses the correct cache line size, and
applies any applicable optimizations.

CPUIDs: F[0-6][1-A] (in /proc/cpuinfo show = cpu family : 15 )

Select this for:
Pentiums (Pentium 4, Pentium D, Celeron, Celeron D) corename:
-Willamette
-Northwood
-Mobile Pentium 4
-Mobile Pentium 4 M
-Extreme Edition (Gallatin)
-Prescott
-Prescott 2M
-Cedar Mill
-Presler
-Smithfiled
Xeons (Intel Xeon, Xeon MP, Xeon LV, Xeon MV) corename:
-Foster
-Prestonia
-Gallatin
-Nocona
-Irwindale
-Cranford
-Potomac
-Paxville
-Dempsey