I see a lot of misunderstand since i post my finding.
In a first place, i started to search why GCN 1.0 was not supported in Rise Of The Tomb Raider last patch.
When Maxwell was accused to not support Async Compute, someone create a program for testing Async Compute. It worked on GCN 1.0, 1.1 and 1.2 back in time.
So i just wanted to verify if that still the case and that how i find that Async Compute was disabled on news drivers. Then i post on Reddit.
After that, many ask me to test a game that support Async Compute on GCN 1.0. So i tried Ashes Of Singularity. You know the end. That just confirm that Async Compute was disabled on news drivers. Old drivers performs way better because of Async Compute.
DirectX12 driver 16.3.1 Async Compute off :
http://i.imgur.com/aiV1pSg.png
DirectX12 driver 16.3.1 Async Compute on :
http://i.imgur.com/CGrb4yM.png
DirectX12 drivers superior to 16.9.2 Async Compute off :
http://i.imgur.com/yiSSRCE.png
DirectX12 drivers superior to 16.9.2 Async Compute on :
http://i.imgur.com/Fch5V8w.png