Intel 6700k @ stock speeds to aid in trouble shooting.
Asus Hero 8 with the latest Bios.
Windows 10 64bit Home.
Dell UHD monitor in DP 1.2 mode using MST.
Assume all current drivers installed for all hardware. On a fresh Windows install and fresh download/install of TW3. And not a power issue as other Games as well as 3Dmark have no issues fully utilizing both GPU's.
GPU usage appears to alternate but is never consistent on either GPU while player TW3, this does not happen on any other Crossfire support title and is only a recent issue for me. For example FO4 scales well and keeps both GPU's loaded.
This graph ( see attached) is from a short snap of game play. Between the red lines is when the game was running with no frame rate cap, Vsync disabled and no FRTC. Both GPU's appear to report 0% - 100% alternating based off which is at 100%.
I used to get 55-60FPS but since this issue occurred it sits at 42FPS.