Look, my graphic card R7 M260

My Notebook
OS: Ubuntu 14.04 64 bits
steam Linux client
Intel® Core™ i7-5500U CPU @ 2.40GHz × 4
16 GB ram
Dell Inspirion 15 5548



The game is running on "2" to "4" fps with all graphic on low , impossible to this play this game with this fps.

Look, i reply this problem to those forums to:
AMD forum : https://community.amd.com/message/2682699#2682699
SteamOS :
https://steamhost.cn/steamcommunity_com/groups/steamuniverse/discussions/1/496880503078970535/
Shadow Warrior Steam forum : https://steamhost.cn/steamcommunity_com/app/233130/discussions/0/490125103639566501/