Left: evolution of cloud (solid) and sink particle (dashed) masses for three turbulent velocity fields. The onset of star formation is clearly seen to be delayed due to the action of turbulent motions that keep dissolving dense structures. The horizontal dash–dotted, black lines denote the masses of observed molecular clouds, like the Perseus MC (PMC; Lombardi, Lada & Alves 2010), the Taurus MC (TMC; Lombardi et al. 2010), and the Corona Australis complex (CA; Alves, Lombardi & Lada 2014). Middle: star formation efficiency for B3M…I… runs. Right: corresponding root mean square velocity of the dense gas. The RMS–velocities converge after turbulence has decayed and global collapse of the cloud has begun. Before this point, the amplitude of the resulting turbulent velocities is determined by the initial conditions.