I have noticed, that after reboot sometimes core clock is fixed to 300MHz or 608MHz. It results 7MHz or 15MHz hashrate in Claymore. To fix this i need to reboot or change core clock manually. I tried running DDU and installing fresh drivers but still no luck.

Has anyone experienced similiar problem?

29MH Low Power bios
Tested on 1xAsus RX 480(Reference) 8gb and 1xMSI RX 480(Reference) 8gb independently
Windows 7 SP1 x64
Latest radeon drivers(16.9.1)