Conversion of a stellar evolution model to SPH and back. Left panel shows a N = 10⁵ SPH realization of a 1 M_⊙ MESA stellar evolution model at 5 Gyr. Right panel shows the HR diagram of the evolution of a 1  M_⊙ MESA model, as well as as the evolution of a MESA model derived from the SPH model, as well as two additional models which where converted at 8 and 10 Gyr of age. As can be seen the conversion at later evolutionary stages induces bigger deviations from normal evolution, probably because of the increased density contrasts (as the core becomes denser) at later times means that the particle distributions induce more mixing.