Sorry, i didn't understood yet.Are you saying you aren't using the boost::random::mt19937 specialization? Because it's there just for people who don't have the background to choose an appropriate parametrization (like me who don't have a PhD on random generators).typedef mersenne_twister_engine< uint32_t, 32, 624, 397, 31, 0x9908b0df, 11, 0xffffffff, 7, 0x9d2c5680, 15, 0xefc60000, 18, 1812433253 > mt19937;The last statement at this section: http://www.boost.org/doc/libs/1_51_0/doc/html/boost_random/reference.html#boost_random.reference.generators