Sags FPS (Euro Truck Simulator 2)

Comrades, help me solve the problem, I play on a license, without mods - yesterday I took Scandinavia at a discount, and terrible frame drops began, it sags to 19. System Fx8320, 8GB ram, GTX780Ti, before that I played perfectly, stable 60, now it's just awful ... Scandinavia returned to the incentive, but the picture has not changed.