The be quiet! Straight Power 12 750W PSU Review: Proficient Platinum Power

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! Straight Power 12 750W meets and surpasses the 80Plus Platinum certification standards, showcasing exceptional electrical conversion efficiency. With a 115 VAC input, this unit delivers an average nominal load range efficiency (covering 20% to 100% of its capacity) of 91.9%, and an impressive 93.2% efficiency when powered by a 230 VAC source. Like most manufacturers, be quiet! received the certification rating with an input voltage of 115 VAC, where the requirements are lower – however, the 750W version of the Straight Power 12 also meets the 80Plus Platinum certification requirements with an input voltage of 230 VAC.

The Be quiet! Straight Power 12 750W PSU doesn't feature a "hybrid" fan mode, which means its fan is active from the start. Thanks to its design, the fan operates at a very low speed even when the load reaches up to 50%, ensuring that the unit runs quietly under typical conditions. As the load increases, the fan's speed increment is modest, designed to keep noise levels down. Despite this conservative approach to fan speed, the thermal control circuitry manages to keep internal temperatures surprisingly low, even at full load. This indicates high energy conversion efficiency paired with a somewhat oversized cooling system, designed to be capable of achieving top performance at minimal noise levels.