Your case is not my one. And it is because calculating becames more complicated. PM developers said that it is a problem of NVidia cards. A year ago or about that I also had 192Mh on 6 cards. MC was +640, PL was 64%, CC was +102 and it costed 750W.

But beginning from about one year ago (may be less) I have time to time decreasing of hashrate and memory overclocking beginning from some values does not increase hashrate. For example now I use for some cards MC +450, but if I will use +640, nothing will bw changed. Moreover, hashrate can be less then if I use +450. So now I have stable 180Mh on 6 cards. And now I use PL 100%, also for one card CC was decreased to +70 (more bigger values does not increase hashrate). And now 180Mh costs me 1000W.

Problem that I was talk about is that MC changes does nothing at all. So with my current settings of CC and PL I had 127Mh on 6 cards.

When I used "-eres 0" (now I use "-eres 1", which also works good) my hashrate was back to 180Mh and hashrate again depends on MC values.

So we are talking about different problems.