[SmG Surreal]

What's probably happening is a bottleneck, your CPU and gpu are overheating themselves, and there's a large power struggle between the two. What I recommend is you buy a more recent gpu like a 1050 or 1060 to balance the two, and if you have a low quality power supply, like a 500W bronze, upgrade that to about a 600W or more silver, then you should be good. Contact me if you have other problems.