It's hard to say. Did it maintain 12 TH/S for long. The drop is not crazy, as there will be ups and downs with hashrate. Do you see anything when you check the miner status page? You might need to post your log to see if anyone can find a problem there.
Yes, It mantain 12TH steadily for a long time.
Okay well for anyone to help we need a lot more info, like answers to
What PSU's you are using?
What are your room temps?
Can you post your logs from cgminer?
Also is it staying at 10.5 TH/S or is it going up and down?
luckily 10.5 isn't to bad.
I am using 1400W PSU
The room temperature around 25 Celsius degree, but I place the miners in front of the air conditioner. Therefore, the temperature should not be the problem.
I try to post the log, but I don’t know how to do it😓.
BTW, I set the voltage offset to +1 now, the average hash rate rise to 11.2TH.
Is it fine for the miner when I set it like that?
Thanks