I have a HP 700-074 that is stock with a i5 4430, 12GB Ram and a 460w PSU. I want to add a graphics card and looking at the Sapphire R7 250 or Sapphire HD 7770 Ghz. The 7770 requires a 450w PSU and a 6-pin(which I have) The R7 250 requires a 400w PSU and 20A. Can someone tell me if I will have to upgrade my PSU either way? Here is a picture of my PSU rail which I don't know how to read (Any help explaining this to me would be good too).