Very Strange thing happened.
I switch from microcoinminer.exe to Cgminer.exe 3.7.2 to mine worldcoin, and my first 280X card slow to 500kh/s
I have 2 pc with four 280x cards in each. Both pc's first card slow down. Other 3 cards in both pc remain 750k. (no overheating issue, no HW error)
I did reboot, reinstall 13.12 driver, reinstall cgminer, reinstall cgwatcher. nothing helped.
It seems that microcoinminer has changed some settings in my system and it affect cgminer.
any help?
You can check engine/memory clock of the card, maybe changed by the miner, if correct try to turn everything off instead of rebooting.
Wait a minute an turn on and try again.