Thank you for so fast answers, but:
1) I have different places for rigs, so Internet connection also different (with different providers too)
2) Interesting idea about electricity, but again, it is 3 different places. But anyway I try check it (don't know, may be try call to electricity company)
3) I have thermometers in rooms, so temp statistic shows ~25C all time (I also have controllable coolers, they depends on thermometers)
4) Virus also good Idea, I try to check rigs with some antiviruses, but I think it is not related
5) I have 4Gb, 6Gb and 8Gb cards, so it is not related to end of epoch
I still researching logs and try found problems. At this moment all rigs online, but I think tomorrow I got few died
1) I have different places for rigs, so Internet connection also different (with different providers too)
2) Interesting idea about electricity, but again, it is 3 different places. But anyway I try check it (don't know, may be try call to electricity company)
3) I have thermometers in rooms, so temp statistic shows ~25C all time (I also have controllable coolers, they depends on thermometers)
4) Virus also good Idea, I try to check rigs with some antiviruses, but I think it is not related
5) I have 4Gb, 6Gb and 8Gb cards, so it is not related to end of epoch
I still researching logs and try found problems. At this moment all rigs online, but I think tomorrow I got few died