Eagle said:
I would tend to disagree. People put to much value on wattage of the power supply, when in fact thats not what you should be looking at. Take that one I listed for example. It runs my computer which is sligtly lower than top of the line. It powers a Athlon 64, 250 GB SATA, IDE DVD burner, PCI-E graphics, and 3 chasis fans. And thats just the devices that plug directly into it. And its only 350W. I don't have it overclocked but there is nothing I see in my monitoring programs that tell me I couldn't. Furthermore I could probably add another hard drive and another optical drive and still have no problems.
But if you think about the future, it might still be a good idea.
The eVGA Geforce 7800GT OC for example, it is recommended that you have at least a 450W supply.
And what if you mix that card with an athlon 64 x2 3800+ with 2 or 3 SATA and alternatively an IDE, plus 4 512 mb memory modules and a lot of external accessories feeding of the USB power plusat least one or two PCI cards, at least one of them a TV card, as well as at least one or two fans (120mm or 80mm) fans in your case?
Take a look at the wattage calculator posted earlier. This amounts to around ~420W according to the calculator, and one must not forget that they only state the average, and cannot be 100% exact.
The 12V rail should output a pretty hefty amount of ampere, and this is why I recommend a higher wattage PSU.