Core 2/newer Xeon

configname: CONFIG_MCORE2

Processor family
└─>Core 2/newer Xeon
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
Select this for Intel Core 2 and newer Core 2 Xeons (Xeon 51xx and 53xx)
CPUs. You can distinguish newer from older Xeons by the CPU family
in /proc/cpuinfo. Newer ones have 6 and older ones 15 (not a typo)