And my logitech unifying usb for my keyboard and mouse. I will also be using some external hard drives on it as well. Not sure if that's valuable information. I've used the wattage calculator on Newegg and this other site but it's telling me about 800w which is a lot and my system isn't even meant to be for gaming or home theater. I know some people who have gaming PC's who don't even use 800w so I thought that was a bit fishy.