WR2 found that review link, which indicates this PSU, while capable of 500W, gets electrically noisy when loaded. Since it WILL be loaded by a HD5850 while gaming, and noise can be damaging to components, the answer is "Sort of, but not really safely, at least not for long." Get a quality PSU now, and save yourself future grief. Antec, Corsair, Seasonic, and Enermax are among the better brands. All of them have full range active PFC (no little voltage switch) and are 80+ certified for efficiency. Five hundred watts is all you need.