This site lol ... First go to any real tech site and see this question been asked 10000 times i have already seen this card melt a 650 and no one with a brain will tell u to run 200 watt less then the reconmended..
Each chip is different, sometimes u win the lotto other times you dont. Just saw u have an i 5 have u searched around to see the max voltages that chip can handle?