Hello. As a note after a discussion [1] I ran into this oddness: $ gcc-6 -march=native -Q --help=target | grep march -march= ivybridge $ gcc-6 -march=native -Q --help=target | grep sse3 -msse3 [enabled] -mssse3 [enabled] $ gcc-6 -march=ivybridge -Q --help=target | grep sse3 -msse3 [disabled] -mssse3 [disabled] It appears that specifying (in this case) "-march=ivybridge" which is the native, isn't enough/the same as specifying -march=native? In addition, the "cache sizes" don't seem to be called out with "-march=ivybridge" as they are with "-march=native" Anybody know what I'm missing here? Thank you! -roger [1] http://stackoverflow.com/a/24213278/32453