Turn off the monitor in some games.What to do?

When playing some games such as bathild 4 at the time when the machine is under water the monitor says no signal the CPU is running 5 seconds and the comp turns off on its own then sometimes it's included in some games but in GTA 5 on ultra settings this does not happen.I think to upgrade hardware in addition to videokarty.What could it be?
Characteristics of the computer processor Intel core ay 3.2 kernel logical CPU 4,motherboard ASUS,RAM 10 gigobayt,videokarta amd radeon rx 580 8 gb with it all is good no problems like,hipro power supply 580 Wat,17-inch monitor.