not with a low PSU like that. Plus factor in age of PSU ( yes they wear down too ) and brand. Your better off buying a new mid-top level 750 watt PSU and getting some cards then. I recomend a 270x while they are cheap. The 7850s , the right ones can be had too cheap. Right now your going to over pay for the 79XX and the 280x and 290x cards/
Thanks for sharing. All cards are still selling with normal price in my city.