Total mass of sink particles as a function of time for the various models. Upper panel shows the influence of the supernova feedback scheme, while middle and lower panels show the influence of the magnetic field. The lower panel shows the SFR (i.e. time derivative of mass) corresponding to middle panel. In the upper panel, run B corresponds to the solid curve, which starts at 120 Myr. The runs with feedback present SFR that are typically 10 to 30 times smaller. Magnetic field reduces the SFR by a factor on the order of 2.