Comment # 111 on bug 109955 from Yury Zhuravlev

Ok, it's many times was here:
echo 7 > /sys/class/drm/card0/device/pp_dpm_sclk

this thing also helped me. Without it, many games make my PC is freeze even
without anything in logs or working ssh. 

Something wrong with the PowerPlay system on Vega cards. Can anybody open a
ticket on the kernel bug tracker?