Sudden short but very annoying lag spikes burst out of nowhere, last for a second happens every minute or so. It is impossible to pvp against people because during every single 1v1 battle a lag spikes happens and means automatic lose.
My computer is extremely beyond capable of running the game, so this is not an issue with my computer. Not other game (GW2, ESO, POE, etc) lag like this, so this is not connectivity issue. Only possible explanation - server issue.