The Enermax PlatiGemini 1200W ATX 3.1 + ATX12VO PSU Review: The Swiss Army Knife

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 Enermax PlatiGemini 1200W PSU comfortably meets the standards of the 80Plus Platinum certification, even though input voltage significantly impacts efficiency. When tested with a 115 VAC input, this PSU achieves an average nominal load efficiency of 91.0% across its operational range from 20% to 100% of its capacity, which rises to 93.2% when operated with a 230 VAC input. The efficiency of the unit peaks at roughly 40% of the unit’s capacity. The efficiency under low loads is quite good as well.

The Enermax PlatiGemini 1200W PSU incorporates a hybrid fan mode, keeping the fan off during low-load conditions to ensure quiet operation. The fan begins to operate only when necessary, which during our testing occurred at loads above 500 Watts, slightly sooner than the unit’s official specifications indicate. The company claim of Zero-RPM up to 60% load is possibly achievable only under ideal laboratory conditions. At typical room temperatures, this allows the PSU to run quietly for most low-to-moderate usage scenarios. As the load surpasses 500 Watts, the fan gradually increases its speed to manage the rising thermal output effectively but never reaches its maximum speed under these operating conditions.