I have had my XFX R7 250x for about a year and i just recently decided to try and overclock it a bit using catalyst manager. When I bumped it up to 1300mHz both of my screens went haywire and my computer crashed. Luckily nothing seemed to be damaged. So i went in, and only went to a 1000mHz boost. My computer stayed running but at certain points my screens would flicker slightly and at one point one even went haywire. So all im asking is, does this seem like a lack of power issue (i only have a 550W psu) or is it something with my card that may now be broken. The card is currently back on its factory settings. My setup is a FX-4300, XFX R7 250X, sound card, wifi card, but nothing else I would thing would be affecting power.