Really Cool and Quiet Power Supplies?

ElanVital Greenerger SSM

General Impressions

Is it really passive?

ElanVital shipped us its EVP-5007-00 power supply, which is not a passively cooled device. The unit includes a 4.72" (120mm) built-in fan that's called on to keep things cool only when the device must supply a maximum load of 500 watts. The fan only turns itself on when it's really needed - and according to the vendor, this should not happen very often. Elan Vital calls this "SSM technology" for "super silent mode."

Power controls for the SSM functions

You can control the SSM functions with a power control on the back side of the device. The SSM setting puts the device into purely passive mode, and won't let the fan run until a temperature threshold is exceeded. The Fan Adjustment Mode setting turns the fan on permanently, but permits fan speed control using a built-in potentiometer. In this case, the temperature sensor keeps operating, and kicks the fan into higher speed if and when the threshold temperature is reached or exceeded.