Mean star formation rate per unit volume in zoom-in region for different models and resolutions: Cen & Ostriker (1992) model (CO92) with stochastic star formation, where ε is the star formation efficiency, a dynamical model with local star formation efficiency (Semenov et al. 2016, S+16), and the Kravtsov (2003) model (K03) with threshold number density n and a fixed star formation time scale of 1 Gyr. The number of levels specified in the legend refers to the number of AMR levels on top of nested-grid levels. Our fiducial model is shown as solid (red) line.