Drawdown in the game (Fortnite: Battle Royale)

I must say that the drivers, while playing the percents do not overheat, the system requirements are met.
To problem, during the game the fps is kept at 70-90, but there are drawdowns for 3-7 seconds to 1-2 fps, then it rises again to previous levels, and so all the time. From the graphics settings, nothing has changed, only the level of stable fps, and drawdown are the same.