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

Hot Test Results (~45°C Ambient Temperature)

During hot testing, the Enermax PlatiGemini 1200W PSU demonstrates a slight decrease in efficiency under heavy loads, with recorded figures of 90.4% at 115 VAC and 92.5% at 230 VAC, compared to 91.0% and 93.2% during cold testing. This reduction is moderate and occurs almost linearly across the entire load range. Despite the efficiency drop, there are no signs of thermal stress, even at maximum load. The PSU is rated to perform efficiently at ambient temperatures up to 50°C and it does so seamlessly.

Under hot testing conditions, the Enermax PlatiGemini 1200W PSU's fan activates promptly and accelerates more quickly compared to cooler environments, increasing almost linearly with the load. As the PSU nears 75% capacity, the fan reaches its maximum speed. This strategy keeps noise levels acceptable up to around 50% load capacity, which corresponds to the hefty output of 600 Watts. As the load surpasses this threshold, the fan noise becomes noticeably louder, making the PSU audibly prominent and clearly prioritizing reliability over quiet operation.

Enermax PlatiGemini 1200W PSU displays a very well-balanced cooling scheme, balancing acoustics with thermal performance. The internal temperatures of the unit as kept consistently low, yet without an overaggressive cooling fan profile that would result to premature high sound pressure levels. At loads above 1 kW, the fan has already reached its maximum speed and internal temperatures will rise a bit more sharply, yet they remain relatively low for a unit with this kind of output, especially for one without a heatsink cooling its primary inversion circuitry.