  We present preliminary results from high resolution magneto-convection
simulations where we find the formation of flux concentrations from an
initially uniform magnetic field. We compute the effective magnetic pressure
but find that the concentrations appear also in places where it is positive.
The structures appear in roughly ten convective turnover times and live close
to a turbulent diffusion time. The time scales are compatible with the negative
effective magnetic pressure instability (NEMPI), although structure formation
is not restricted to regions where the effective magnetic pressure is negative.
