Xorg totally freezes after a while while using picom or playing 2d or 3d games

[chris greek]

Xorg totally freezes after a while while using picom or playing 2d or 3d
games
If i don't use picom it doesn't seem to have a problem but i tried playing
a 2d game and also freezed.
  I have an R7 240 with 2Gbytes of Ram , my pc has 8 Gbytes of ram
I don't know what is the problem but it always happens
The xorg freezes and i can't do anything if change into a console and don't
kill Xorg it completely freezes the pc and can't switch to a console
anymore.