That PSU is the absolute minimum according to the card's recommended power supply wattage. However, the actual total power draw for an HD5770 is about 200-250 watt (total system draw). I'm not saying that it's okay to run the card with your power supply, but more than likely it will work. The problem is that your PSU might not be as efficient as a PSU from a well-known company like Corsair or Seasonic. I'd recommend a PSU upgrade just to be safe.