  We study a comprehensive list of quantum codes as candidates of codes to be
used at the bottom, physical, level in a fault-tolerant code architecture.
Using the Aliferis-Gottesman-Preskill (AGP) ex-Rec method we calculate the
pseudo-threshold for these codes against depolarizing noise at various levels
of overhead. We estimate the logical noise rate as a function of overhead at a
physical error rate of $p_0=1\times 10^{-4}$. The Bacon-Shor codes and the
Golay code are the best performers in our study.
