My second r9290x always remains idle no matter what, crossfire in DX11 seems to have a negative effect. Why is corssfire not working in DX12?
You need version of Deus Ex: Mankind Divided v1.12 build 667.0 and win10 with all updates and last AMD driver
I'm not sure about last patch, but in earlier versions MGPU could be activated by this instruction:
To activate Multi-GPU DirectX 12 you are required to do the following:
Retrieving data ...