NEEDS HELP TO CHECK THIS PSU 's stability

[yuxuan]

I recently bought a new PSU

which is silverstone strider essential 600watt model.

I tested this PSU in OCCT with power supply section, when the graphic test loaded it began to run very smooth and high fps,but after few seconds the fps started to fluctuated so many, and caused serious lag, means it can be suddently smooth with high fps and suddently laggy with low fps.

so does this mean that my PSU is unstable and needed to be replaced?

my spec

Prossecsor: i5-3470
Motherboard: Asus P8H77-M LE
RAM: CORSAIRVENGEANCE LP 1866 8GB
GRAPHIC CARD: GIGABYTE GEFORCE GTX660 TI 2GB DDR5 OVERCLOCK

THANKS apperciate

 

[yuxuan]

graphs in 3v, 5v and 12v show decline in volts while the fps is droping