Occasionally the game freezes, causes the PC to work the HD a lot. This results in stutters and eventually, lockup, which shows a "Arma 3 stopped working" error upon ctrl+alt+deleting to the program manager.
Also occasionally the game causes the graphics card to completely fail, with the screen covered in colorful artifacts and flickers, followed by a total lockup requiring a cold start (reboot from push-button on the PC case, since all key-strokes are not registered anymore. Total lockup is indicated by numpad light stopping to switch.).
This seems to appear only when playing Arma, often occuring minutes to hours after the game has been started and closed again. I have not been able to reliably reproduce this error, but it has been occuring occasionally with the past three devpatches. {F22019} {F22020} {F22021} {F22022} {F22023}