Is there any stress test to ensure my whole pc works fine with this psu and wont fail.
Would prime 95 do this?
Nothing outside of a laboratory environment. That's why it's so important, IMHO, to use the highest wattage quality PSU you can afford. The less you stress a PSU the more consistently it performs and the longer it lasts. It's not like a CPU that will be outdated in a year. It's the cheapest insurance policy you'll ever buy for your new rig.