My guess is your power supply for your over-clocked machine--can you swap it for a second and monitor to see if it continues to be difficult?


I tried with a Power Supply ANTEC HCP 1200W and after 3 hours de hash rate downgrade to 385 GH/s from 510 GH/s I dont understand why....
I think its not power supply. Maybe the temperature? Its operating at 47-43 ºC.... I think is not an excessive temperature...

lliixi you should start low then after a few hours up the frequency to the next until you find where the miner is stable. 212.5 is a good starting point then 218.75 and so on. Many here have been down this road and there is no specific setting for all to follow, what works for one unit may not work on another. You may also look back at the previous pages to see what everybody here has gone through to get a stabilized unit. Trial and error my friend.