lagi fifa 17 (FIFA 17)

Played all year in fifa 17, all was fine, no lag and in the spring began to lag, and not only in multiplayer but in single player, the game is, but there are friezes, which slow down the gameplay, although it never happened before. Downloaded fifa 18 demo, started the match, too, everything was fine, no lag, and after 30 minutes of playing time, beginning to podslushivaet. Who knows what could be wrong? Earlier after all it was no lag. Now I doubt whether to buy fifa 18.