Originally Posted by KennyT772
What you can look for is the amount of 12v rails X the amperage of the smallest rail (say 18a for my ocz) then figure 3/4 of it is useable to prevent over loading. For economical users not overclocking and not upgrading a 450w-500w will give you the best efficiency (25-50 percent load is where max effciciency is reached) and will give you a long lifetime.
What I was saying in my other post is that you cannot go only by the wattage or amps, you have to take both into consideration for the best choice on output. After you figure what you need in terms of power you then need to find a suitable company to buy a unit from, with the extra features you want such as modular, pfc, low dba, etc.
ok so for a four rail psu you only add 3 rails together to get accurate picture of amp supply
but what do you do if its a two rail psu? is that still 75% of the total?