Going to one HD 4550

CWO4 Dave Mann

The question is--what's you're goal in tinkering? My comments are heavily oriented toward quiet PCs because that's what I'm into. However, if you're not (yet) bothered by your computer noise, then reliability and sheer computing power are probably more sensible goals.

Generally a bigger fan with slower revolutions is quieter. However, sometimes multiple fans are better in the case of 80mm vs 120mm. Interestingly, for a given amount of airflow two 80mm fans tend to be quieter than one 120mm fan.

At any rate, 80mm and 120mm fans are the only serious contenders for silent computing. Smaller fans have insufficient airflow when undervolted to quiet levels, and larger fans are too loud even when undervolted to minimum levels.

You have a misunderstanding with how PSUs work. A 500watt PSU will work exactly as hard as a 150watt PSU when running the same equipment, doing the same things. What makes a difference is the efficiency level--and this is not trivial to pin down because efficiency is different at different loads. You can get accurate test results of efficiency curves at reputable review sites (like silentpcreview).

There is no relationship between advertised wattage rating and efficiency levels.

Isaac Kuo