Sorry for later. I don't use AMDGPU, (still) using RADEON kernel driver. But, this seems to same issue. I install fancontrol and set parameters of /etc/fancontrol , this issue seems to be fixed. Thanks for your advice. Regards, Ohta. # I'm using SAPPHIRE's RADEON HD7770 GPU board, and ASROCK 990FX Extreme4 mainboard.