Most common symptoms of an under powered psu:
bad 3D performance
freezing during gameplay
PSU overload can cause it to break
But that doesn't mean a bad PSU is always the cause of the above either.
That's not to say you would get all of those issues depends on the quality of the PSU and how many amps it has things like that.
It can't hurt to have a better PSU really, it is always better to have too much power available than too little.
Thank you for answering my question my friend, I am so happy that I could get an answer for my question.
just anothwr question:
Should I get the minimum requirments (650 watts) or maybe (750 watts) Thanks anyways =]
Depends what you can afford, if it were me I would go for the 750W one for peace of mind.