Thx for the info, but ur answer doesn't match my question. I'm not talking about Dx12 Games, I am talking about Microsoft DX12 itself. When u enable the mGPU option, both GPUs will lose all DX12_2 features in the system.
What does it mean? It means either Microsoft or Amd disabled DX12_2 features when ur using more than 1 card. U can't not use Ray tracing with 2x 6900xt, and that has nothing to do with games. IT IS DISABLED BY DX12 OR AMD DRIVER. System info shows that the hardware (2 x 6900xt) doesn't support DX12_2...
I have asked both AMD and Microsoft MANY TIMES, and they know nothing! They don't even have relevant documents to look up. I really wish those engineers could test it before launch it! If you cannot support all the features, you can choose not to publish/not promote. It is unacceptable to release a prototype as a finished product, whether it is software or hardware.