The be quiet! Pure Power 12 M 650W PSU Review: Solid Gold

Cold Test Results (~25°C Ambient Temperature)

For the testing of PSUs, we are using high precision electronic loads with a maximum power draw of 2700 Watts, a Rigol DS5042M 40 MHz oscilloscope, an Extech 380803 power analyzer, two high precision UNI-T UT-325 digital thermometers, an Extech HD600 SPL meter, a self-designed hotbox and various other bits and parts. For a thorough explanation of our testing methodology and more details on our equipment, please refer to our How We Test PSUs - 2014 Pipeline post.

The Be quiet! Pure Power 12 M 650W adheres to the 80Plus Gold certification criteria, demonstrating commendable electrical conversion efficiency. Specifically, when supplied with a 115 VAC input, the unit exhibits an average nominal load range efficiency (spanning from 20% to 100% of its capacity) of 90.7%, and 92% when powered by a 230 VAC source. The peak efficiency of the unit takes place at 50% load and is at 93.4% or 92.6% for an input voltage of 230 VAC or 115 VAC respectively. These figures align well with expectations for a product within its efficiency class.

The Be quiet! Pure Power 12 M 650W PSU does not feature a "hybrid" fan mode, resulting in the fan being operational from the moment the power supply is activated. However, due to its design, the fan maintains a low speed for up to 60% of the load capacity, which helps in keeping the unit operating quietly, especially under standard conditions at room temperature. As the load surpasses approximately 400 Watts, the fan's speed increases significantly to address the increased thermal output of the PSU. The internal temperatures of the unit remains low at all times, with the thermal control circuit being particularly aggressive when the load is greater than 500 Watts.