  It has been suggested that Glauber (inflow) and Sznajd (outflow)
zero-temperature dynamics for the one dimensional Ising ferromagnet with the
nearest neighbors interactions are equivalent. Here we compare both dynamics
from analytical and computational points of view. We use the method of mapping
an Ising spin system onto the dimer RSA model and show that already this simple
mapping allows to see the differences between inflow and outflow
zero-temperature dynamics. Then we investigate both dynamics with synchronous,
partially synchronous and random sequential updating using the Monte Carlo
technique and compare both dynamics in terms of the number of persistent spins,
clusters, mean relaxation time and relaxation time distribution.
