what size of a power supply will I need for a AMD64 3200+, 160gb 7200 rpm drive, dvd-burner, dvd-drive, floppy, eVGA 6800gt, sound card, msi K8n NEO platinum, and a thermaltade cpu fan. I was looking at a Thermaltake 480 watt power supply. thanks for the help
its not all about watts guys...you have to think amperage more than watts
you will want at least 16 amps on the 12v rail...
you want to get the lowest watt PSU you can find because they run cooler and use less electricity.
In actuality, wattage is irrelevant; much like how Mghz is irrelevant with CPU's(a 2.8ghz celeron does not perform better than a 2.0 ghz athlon xp)---all you should look for is high amperage...15 amps is minimal, 16 amps is adequate for most apps...higher is better.
I've got a book of matches,
I've got a can of kerosene,
I've got some bright ideas involving you and me.
Actually, you don't want to get the lowest watt PSU you can find. If your computer uses an average of 150 Watts (continuous), then your PSU will only draw what it needs from AC. If you have a 400 Watt PSU and its AC/DC conversion is 400/150, then you have an incredibly inefficient (and crappy) PSU. Your talking about a 37.5% efficiency for the above numbers. That means your wasting 62.5% of electricity. In my opinion, the minimum acceptable range of efficieny should be no less than 60%. Again, a good PSU will only draw what it needs. A better conversion rate for said PSU could be 400/280 or 214/150 (eff. 70%) So, you can buy 600 Watt monster from Enermax for a budget PC, even though it is a bit overkill.
But I wholeheartedly agree with you about amperage. That's one stat that doesn't get enough attention. Technially, when picking a PSU, you want to make sure all is up to your standards, including amperage on rail lines.
Actually, I do somewhat agree with you about low wattage PSUs. If you only need, maybe, 200 Watts continous, typically, the lower wattage PSUs are better because higher wattage PSUs atypically convert efficiently for lighter drawing rigs compared to the former. There are, though, high wattage PSUs out there that have decent efficiency at lower conversion, as well as higher conversion.