So I currently have an essentially stock HP P7-1174 (I've only put in a new hard drive can't think of the model off the top of my head right now and am not home.) Will the R7 260x work with my PSU or should I go for a new one? It's 300 Watts here's a link to the computer specs http://h10025.www1.hp.com/ewfrf/wc/document?tmp_forceView=desktop&cc=us&dlc=en&docname=c03005744&lc=en