White Screen when running Mantel

White Screen when running Mantel
Logged in to Steam started Star Swarm ran D3D no problems other than not utilizing both CF GPUs.

Using default settings I:
Click to run Mantle and screen goes immediately to White
However Processor and GPU Utilization increases as expected
as if it is running in the background of this white screen
not sure if it would run the full 360 seconds
Ctrl+Alt+Delete end process

System specs:
Recent clean Install Win8.1x64 Pro (All Current)
4770k @ 4.3 (STABLE)
2x Ref 290x (14.12)(Stock Clocks)
16GB 2x8 2400 DDR3 XMP1
HX850w psu
Creative SB-Z

dxdiag
https://docs.google.com/document/d/1kyUlqwtKRnOF5Vo8v07SqlaJzbN8enZtTtVXs4oxiLM/edit?usp=sharing