A comment is made on the limits of the determination of crystal structure from X-ray powder data, special emphasis is made when laboratory equipment is used. It is shown that the cell-volume is the main limiting factor, while the symmetry of the crystal metric in the pattern, the lack of evidence of the twin effects and the low accuracy of the intensity data are inherent to the techniques and hinder the crystal structure determination. Peak broadening produced by the sample-dependent contributions and layered structures increase this bound.