I noticed this today ... Kinda strange, not sure what's up with it. Thread 4 and 5 are slightly lower, because that's the card with the dummy hdmi in it, but thread 12 is way lower than normal. Not sure why that is. Something else to note ... With the old version of XMR STAK, I never got much above 11,500 h/s and all cards were looking normal as far as individual hashrate.
Sorry for deleting the picture, just do not want to make this page harder to load, that's why I've removed it.
What tool are you using to monitor your cards?
I dropped mining XMR and currently I am on ETN, might not be as profitable as ETH and XMR, but my power draw is 500W from the wall and I see some potential growth, which in the long run might pay off better imo
Hope I'm not wrong!