Yea um PSU is important. I heard one time if your PSU is toos trong is burns up. I was told thats a complete lie by everyone besides one person, and that person told me in the first place. So yea but get a beter PSU your rig to big for a 280. He may have been "technincally" right as in thats all you needed but he didn't factor in that PSU not actually giving out that much power or you possibly going over the limit. If you even go over the limit of a PSU by a few watts it'll shut down. It'll onyl give you so many watts then go down.