Crash without BSOD while playing games.

Recently my computer has begun to crash in the middle of games (Counter strike and League of Legends). The crash happens abruptly while playing, the screen tears the image completely where nothing on the screen is now identifiable, just shreds of the image/colors/pixels. The PC then stops all tasks and continues to run with the frozen image on the screen with no sound or anything running. I have to hard reset and hold the power button. The computer runs fine right after, a slow boot up at most. I know my CMOS battery is dying due to the clock on my computer losing time. Is could that be a problem linked to this?

I'd appreciate any help. Thank you.

Is there a way to verify that's the problem? I know my computer reaches around 60-70c When playing games. I've read that those are "okay" since it's under load. I've got a stock cpu fan as far as cooling goes.