CONFIG_IA64_SGI_UV is not available for thedefaultarchitecture x86.
Result is shown for architecture ia64

SGI-UV

configname: CONFIG_IA64_SGI_UV

System type
└─>SGI-UV
In linux kernel since version 2.6.26 (release Date: 2008-07-13)  
Selecting this option will optimize the kernel for use on UV based
systems, but the resulting kernel binary will not run on other
types of ia64 systems. If you have an SGI UV system, it's safe
to select this option. If in doubt, select ia64 generic support
instead.