32bitマシンでやってみた。 %uname -a Linux (ホスト名) 2.6.18-92.1.13.el5 #1 SMP Wed Sep 24 19:33:52 EDT 2008 i686 i686 i386 GNU/Linux % more /proc/cpuinfo | grep "model name" model name : Intel(R) Pentium(R) Dual CPU E2180 @ 2.00GHz model name : Intel(R) Pentium(R) Dual CPU E2180 @ 2.00GHz %time ./a.out 65533 2862984010 ./a.out 31.00s user 0.01s system 99% cpu 31.304 total