Computer restarts under stress

-Khaotic-

Commendable
Jul 23, 2017
5
0
1,510
This has been bugging me for a few days recently, every time i play a game about 30 minutes in my computer restarts and it's generally accompanied by ASUS anti-surge protection.
i've done a few stress tests and have noticed that my temperatures are fine and that they won't cause the restart. However my PSU has been getting incredibly hot, i don't know if this has anything to do with it. I did another stress test but checked the voltages and saw that when it's about to crash the voltages rise way above normal (http://prntscr.com/fzaur7)
i'm thinking of buying a new PSU but i'd like to know if the PSU is the problem

Build:
CPU QuadCore AMD FX-4300, 3900 MHz
MOBO Asus M5A78L LE (3 PCI, 2 PCI-E x1, 1 PCI-E x16, 4 DDR3 DIMM, Audio, Gigabit LAN)
GPU MSI GeForce GTX 750 Ti
PSU PowerCool 550W PSU - PSUPC550AUBAM
RAM 2*4GB ZEPPELIN 4GBD31333
HDD 2*499GB don't know the brand