I'm thinking in repleacing my Celeron 533 o'ced to 900 in a Bh6 into a Duron 600 o'ced to 1ghz. I currently have a 3 year old 250 watt ATX power supply which has not given me any trouble so far and I have three Cd/Dvd/Cdrw drives with 4 inch power hungry case fans. To keep me stable with Duron, Thunderbird etc. do I need to buy a 300W power supply and does it have to be certified with AMD or can it be just generic? I believe that certification fiasco was with Amd 750 chipset mobos which and old .25m Athlons.