Answer

Solution: Gaming APP ver. 6.0.0.09
Root Cause: Gaming APP using Nvidia and AMD graphic card API to decide whether the GPU core clock will drop or not when there's no loading. Nvidia original API set the GPU core clock to drop automatically but AMD graphic API set the GPU core clock not to drop automatically. Now SW team discussed with VGA team and finally decided to modify Gaming App to drop GPU core clock when AMD cards connected.