Hladaj si v nastaveniach scaling mode. Default ma byt ten prvy. Typicky to tam ale ma byt len pre interne displaye ntb. (ak to tam amd nacpal aj pre externe displaye, tak si to hladaj v nastaveniach u toho displaya.
http://support.amd.com/en-us/kb-articles/Pages/Una bleToSetGPUScaling.aspx u teba to bude asi uz inde ak mas nejake nove ovladace