  We study numerically the phase-ordering kinetics of the site-diluted and
bond-diluted Ising models after a quench from an infinite to a low temperature.
We show that the speed of growth of the ordered domain's size is non-monotonous
with respect to the amount of dilution $D$: Starting from the pure case $D=0$
the system slows down when dilution is added, as it is usually expected when
disorder is introduced, but only up to a certain value $D^*$ beyond which the
speed of growth raises again. We interpret this counterintuitive fact in a
renormalization-group inspired framework, along the same lines proposed for the
corresponding two-dimensional systems, where a similar pattern was observed.
