Power supply help

Might I Suggest

http://www.newegg.com/Product/Product.asp?Item=N82E16817153023

Its got 430 watts. Its 39 bucks with a 10 dollar rebate. Not bad for 29 bucks.
NEWEGG FOR THE WIN

 

I've never seen a desktop computer that was made in the last five years draw more than 30 watts or so from the wall, so you might not need to upgrade at all.

That said, the supply in Swifty's link is from a reputable manufacturer, and you can't go wrong with the price.

 

http://www.newegg.com/Product/Product.asp?Item=N82E16817104953

I dislike and dont trust ThermalTake but... I would reconmend the FSP one even though it doesnt have sleeved cables. A bad PSU will kill your computer spend a little more money and get a better one.

 

Yes, but isn't that taking into consideration the source feed of 120 volts AC? If I understand correctly, the rated "wattage" of the PS is the output on the DC side totaled amoung all the various DC voltages present, not the draw wattage the supply pulls from the AC line in the wall.

 

That's absolutely correct, the rated wattage of a power supply is the output wattage, or the number of watts that can be drawn by devices attached to it before its internal resistance causes it to be damaged. Watts are a measure of power used (1 watt = 1 joule of energy per second), which doesn't vary when passed through a transformer circuit. When the transformers in a power supply change the voltage, the current, measured in amperes, changes (amperes = watts / volts). The best way to explain it is that the devices in your computer draw a certain amount of power from the wall, and the power supply converts 120 VAC to 12/5 VDC so that the devices receive the voltage they were designed to work with. The power supply doesn't draw much power to speak of on its own, it's just a converter (it actually consists of two transformers to convert 120 volts to 12 volts and 5 volts, then rectifiers (diodes) to convert AC to DC).

Anyway, I'll stop boring you with the EE lecture. Suffice to say that the wattage drawn from the wall will be slightly higher than the wattage drawn by all the computer's components combined (taking into account that the power supply itself isn't 100% efficient -- some power will be used in the conversion process). Computer components don't use nearly as much power as their manufacturers claim, though they might under full load. Of course, modern operating systems and bus architectures being what they are, I doubt the total load ever gets beyond 5-10%.