just to defend Solaris a little bit. This OS's gcc compiler by *default* produces 32bit applications even on amd64 hosts and even Solaris 11 is 64bit. On the other hand majority of Linux distros for amd64 are pure 64bit which means also their gcc compilers produce 64bit apps. As amd64 is way much better in perfromance than pure old x86 I would really strongly recommend to rerun the benchmarks and enforce 64bit app compilation on solaris by using `-m64' switch. Nothing more is needed.