I did not see any other posts on this, but will apologize in advance if it has been addressed elsewhere. At any rate, I have found a significant drop in the hash rate when running Bitcoin on an Atom 330 processor after version 0.3.12. On a 1.6 Ghz Atom 330, 0.3.12 yields a hash rate of approximately 850 khash/s, while under 0.3.13 and 0.3.14 it drops to barely over 500 khash/s. I have two such machines and the results on both are virtually identical. They are both running Ubuntu 10.04, I have not tested under any other OS.
Several other 32 and 64 bit processors I have tested show no degradation since 0.3.12. Does anyone happen to know if there were any changes between 0.3.12 and 0.3.13 which might be adversely affecting the Atom 330 or perhaps SMP processors in general?