The Corsair RM750e ATX 3.1 Review: Simple And Effective

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 Corsair RM750e 750W PSU comfortably meets the 80Plus Gold certification requirements, despite the notable impact of input voltage on efficiency. When tested with a 115 VAC input, this PSU achieves an average nominal load efficiency of 89.5% across its operational range from 20% to 100% capacity, which increases to 92.4% with a 230 VAC input. The efficiency drop of 2.9% due to the input voltage is perhaps the highest that we have seen to this date, but that has no other effect on the unit’s performance or quality. The efficiency peaks at a load near the midpoint of its capacity. The efficiency under very low load conditions is mediocre.

The Corsair RM750e 750W PSU features a hybrid fan mode, allowing the fan to remain off under low-load conditions to maintain silence. The fan begins operating only when thermally necessary, which in our tests occurred at loads exceeding approximately 150 Watts, a fairly low load point. At typical room temperatures, this means the PSU operates quietly while the system is idling but is unlikely that the fan will stay off with as much as a hint of system load. However, even though the fan starts, it maintains very low RPM up to roughly 500 Watts, with the RM750e being practically inaudible up to that point.

Overall, we really only see the fan on the RM750e really ramp up when the PSU approaches its maximum load – roughly the last 100 Watts from 650W to 750W. Though even then, there's more than enough cooling capacity to allow the fan to remain below its maximum speed.