Question PC restarts

[AleKattax]

My pc restarts when CPU and GPU are used at about 100%;
for example when I'm on call of duty bo4 when I lock my fps on 60 it doesn't crash but when I don't lock my fps it does crash.
In stress tests my GPU doesn't crash on 100%.
Before the pc restarts classic overclock artifacts appear.
GTX 1660 super 6GB ; Max temperature at about 66 degrees with fan at 75%; with fan at 30% max temperature is 78 degress
i5 9400f . Max temperature : 65 degrees
PSU Rotoro builder edition 600w
My GPU has 1785 MHz boost frequency but it reach 1920 MHz when i'm playing. I'm italian; sorry for the bad English. Thanks

 

[Lutfij]

Welcome to the forums, newcomer!

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list them like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:

You might want to also see if you can source a PSU that is reliably built from a friend or neighbor to rule out the PSU you currently own is faulty or failing.

 

[AleKattax]

• CPU: Intel® Core™ i5-9400F
• Motherboard: Gigabyte GA-H310M-S2H
• GPU: Manli GTX 1660 Super 6GB
• RAM: DDR4 G.Skill Aegis 16GB 3000Mhz
• SSD: Kingstone A400 SSD SATA 240GB 2,5″
• PSU: Riotoro 600W Builder Edition
• Chassis: Noua Diamond
• HDD: toshiba-p300-35-3tb-7200rpm-sata-6gb-s-bulk
• OS: Windows 10 pro last version

I'll try another PSU when I can