This is fun! $ clang -mtune=native -march=native -fomit-frame-pointer -O3 -o knuth_search2 knuth_search2.c $ ./knuth_search2

This is fun! $ clang -mtune=native -march=native -fomit-frame-pointer -O3 -o knuth_search2 knuth_search2.c $ ./knuth_search2 naive search average: 65025704.00 ns knuth search average: 76994680.00 ns and $ gcc -mtune=native -march=native -fomit-frame-pointer -O3 -o knuth_search2 knuth_search2.c $ ./knuth_search2 naive search average: 65636020.00 ns knuth search average: 64689948.00 ns knuth_search2 is your modified code but with 100mb arrays.