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

SGI-UV support

configname: CONFIG_IA64_SGI_UV

Linux Kernel Configuration
└─>Processor type and features
└─>SGI-UV support
In linux kernel since version 2.6.26 (release Date: 2008-07-13)  
Selecting this option will add specific support for running on SGI
UV based systems. If you have an SGI UV system or are building a
distro kernel, select this option.

is selected by