there was a reason nobody recomended brands like "rocket fish" and that is because low end PSUs = bad news.
It says 550W, it will probably put out 450 at the most constantly, probably less, and peak at 550W.
It will be made of cheap components that will end up blowing and taking out several components with it, probably your new 4850. If you are lucky it won't but then you will have learned your lseeon, wasted $42 and have to pay a decent price for a decent PSU, like one of the ones listed.
thanks for pissin in my wheaties lol