Evolution of the total magnetic energy in units of the initial value for the 3D Orszag-Tang vortex test. We plot the result from three different tested resolutions [n_x, n_y, n_z]=[128, 148, 12],[256, 296, 12],[512, 590, 12] done in GDSPH. We also include a TSPH case with n_x = 256 and the n_x = 512 curve from Wurster et al. (2017) for comparison sake. We can see that there are no visible difference between the TSPH (purple curve) and GDSPH (brown curve) cases. From the figure, it is also clear that the GDSPH case of n_x = 512 (magenta curve) is less dissipative than the simulation from Wurster et al. (2017) (grey curve). Significant differences between resolutions can be seen to occur at later times during the evolution.