View Full Version : How Do They Come up with the wattage on a Power Supply

05-05-07, 07:35 AM
I was looking at BFG Tech 800watt power supply and I looked at the output
3.3v-26amp-5v 26amps-12vx4rails 54amps combined-12v.8amps +5VSB 3amp
these were the spec's at BFG site but looking at newegg everthing is the same except the 3.3v is 24 amps and the 5v is 30 amps
Then I look at my SilverStone OP 650 watt and it is 3.3v-24 amps 5v-30amps
12v 54amps -12v-.5amps +5VSB 4amps,one is a 800watt and one is a 650 watt but they seem to put out about the same.

05-05-07, 11:18 AM
Hmm, I did this in college one time to calculate amperage with voltage and wattage

Wattage / Voltage = Amperage
Voltage * Amperage= Wattage
Wattage / Amperage = Voltage

So now you can calculate how many watts on each rail ;)