Mouse Lags (Spellforce: The Order of Dawn)

I looked through the topics, maybe I could not find the answer. I wore the internet, I don't see anything like that either. The problem is that the game begins to fiercely slow down the game, when you move the mouse, and when you select an army. What is the second part, what is the first .. Computer characteristics are hardly needed. Mouse x7 without add. BY.