Had a few of these for a while now and they have been fine averaging the advertised 500MH each at the pool.

As you know, when the DAG changes they start again with the tuning and it takes around an hour to get back up to normal speed.

However on the last DAG change the speed on them all has plummeted and they are only getting around 430MH.

Wondering if anyone else has observed this.  I have machines at 2 locations which sort of rules out it being an issue at my end.