We study conserved models of crystal growth in one dimension ( _t z (x ,t ) = - _x j (x ,t )) which are linearly unstable and develop a mound structure whose typical size L increases in time (L ~tⁿ ). If the local slope (m = _x z ) increases indefinitely, n depends on the exponent characterizing the large-m behaviour of the surface current j (j ~1/|m | ): n = (1/4) for 1 3 and n = (1+ )/(1+5 ) for >3.