Hi, I've seen GROMACS (which is said to be the World's fastest MD :) ) compared with AMBER, CHARMM and GROMOS96 in J. Mol. Mod. 7 (2001) paper. Have anyone compared speed of GROMACS and LAMMPS or DL_POLY or GULP? Marcin -- Marcin Wojdyr | http://www.unipress.waw.pl/~wojdyr/