When to use a 300 watt vs. 350 watt vs. 400 watt power supply?

[rnmcd]

Is more watts always better?

Do some processors or mobos require a minimum wattage power supply?

One reason I ask is because I bought a 300 watt power supply to replace the one in somebody's PC then I discovered that wasn't the problem...anyway, the place that I bought it from won't take it back but they will let me pay the difference for a power supply with more wattage. I was just wondering if there would be any advantage to buying one with more wattage.

Thanks

 

[bjc112]

Quality of quantity...

Some 350w are just as good a no name generic 450...

 

[redhatlinux]

The total wattage rating of a Power Supply is really not much to go on. Its rare that you will exceed the 'total' But, each individual voltage has its own limitation, and its often different between supply brands. Next, consider that most supplies ( not the TRUE Power) have a limit of the total of the +3.3 and +5 combined which is substantially lower the the total limit of the two voltages individually. Consider that Athlon systems pull most of their power from the +3.3 and +5 and this limit becomes very important. Intel and some of the newer Athlon mobos use ATX(12V) supplies which use DC-DC converters on the additional 12v lines to provide CPU core voltages.