5 cathode tubes, 8ft neon string, 4 cathode fan grills, and 6 fans = 100+watts. Thats a huge chunk out of my 350w PSU. And i have a 9800 pro. I also have an extra 200w PSU, so i can save money instead of spending it on a 550w PSU. I also seen modded PCS with 2 PSU sucessfully supplying power to all their parts.