oh tahiti now i see. probably does not support overdriveN, just older versions
well it shows overdrive tab in AMD drivers gui & i am controlling it with overdrive5 tool...
https://github.com/BackupGGCode/overdrive5- take a look (opensource) its old but gold - working r9 to vega flawlessly.
right, overdrive 5. atm overdriveN only supported by miner. when i finish the important stuff i will look into it.