To operate power supplies throughout their power ranges while consistently maintaining minimal operating noise is a vital cornerstone of our corporate philosophy. That is why, for us, working in a certified anechoic (practically echo-free) room is enormously important. (See: INSIDE be quiet! - the Straight Power 10 Story)
Just optimizing a fan curve for many different load conditions is a lengthy process—one which we do at higher temperatures then would normally occur in the homes or offices of end users. Whether we are considering the steady operation of a newly developed fan at extremely low speeds (200 rpm) or the sovereign cooling of components under extensive full load, our goal is clear: from the second we start planning, our focus is on developing the quietest power supply we can in each and every class. The actual development and testing phase for a new PSU design usually lasts more than six months. If any technical changes are made, we repeat the entire test suite. It is also important that we don’t just let other people perform our tests: we always have our own professionals present to execute or support all tests. From past experience we have learned that this is the only way we can be sure to meet our high standards of product quality.
Another important issue for us is that we never allow our power supplies to operate right at the limits of what is allowable; we always over-engineer to achieve optimal results. For example, standards say we could allow our PSUs to be ‘just good enough’ in the area of electromagnetic compatibility, but we won’t. We always design to be far within regulated maximal limits. The effort and costs required are much higher this way, but doing so allows us to guarantee that our power supplies comply with all standards and regulations, under all conditions and despite manufacturing variability.