Departures from games

Hello, I have this problem: I have the games with high graphics work load and with average load begins to freesite. Was couples graphics card in 2k16 in conjunction with not a very powerful processor which uploaded it high on 40 to 50 percent. Recently bought a more powerful processor. Put, looked, load none 100% happy, I played an hour 2-3 games, 2 hour games FPS dramatically dropped to 15.I thought that was throttling. But the next day PC, downloaded it, played for about 15 minutes, and then crashes error (display driver stopped responding and has successfully restored). Changing drivers did not help(it helps only to restart PC). Can we fix?
In the service center shrug.