Originally Posted by charliehorse55
EDIT: There are actually many good reasons to be well below the maximal wattage of a PSU, such as efficiency, silence and low ripple.
Efficiency is actually generally quite poor at low load levels. 40-60% is usually the sweet spot, give or take 10%. Below 20% efficiency usually drops of precipitously. And since most computers spend the vast majority of their time idle you want idle efficiency to be better.
As for ripple... What are you doing with a power supply with poor ripple to begin with? You've read my article, I'll wager.
Silence; again, most of the time the computer will be idle so the fan will be quiet no matter what. Only under load will a fan ever become loud; and in quality units it's still usually fairly quiet, eclipsed by CPU and GPU fans.
Overkill isn't necessarily a bad thing. I have to overreact to many things simply to ingrain into people that they don't need
a 750W power supply for their 5770, that they don't need
a 1200W PSU for their dual GTX460s, and that those situations give little real benefit. It might not hurt, but consider: the more people see rigs with excessive power supplies the more they might start to think that a given card or configuration requires XXXWs to run. And then they
go overkill. Until you get people like those *******s over at TechSupportForum who require
at least 550W for a Phenom II and an 8400GS, or the fools telling the guy with a GT220 to get a 750W "in case you go SLI" (GT220 can't even do SLI).
Overkill isn't necessarily bad, but I make my recommendations with reason, as a braking action on the excessive recommendations made by people who don't understand how much power a system really uses. I do undermine my own point by having a 1200W power supply, but that's only because it performs better at my typical loads than any other power supply I have at the moment.