There is no i5 1156. 1156 is the socket, not the chip. 95W is what matters however. 95W CPU + 50W or so for motherboard/breathing room + 150W for the GPU = 300W total. Any PSU that can output 300W on its 12V rail(s) can be used. This means good 380-450W units, and just about all 500W units. If you want to maybe run two GTX460s later, tack on another 150W.