Fractal Design Integra M 550W 80Plus Bronze Power Supply Review

Efficiency, PFC and Voltage Regulation

Voltage Regulation

To test voltage regulation we load the power supply to five different load scenarios that give an equal spread of load across every single rail. So that means 20% on all rails, 40% on all rails and so on. We then calculate the average deviance of each rail from its expected voltage.

The voltage regulation on this unit was fairly good, but certainly nothing too fancy. I generally aim for under % deviance, but the 5V rail was running a little hot, but still well within safe margins. The one that really matters, the 12V1 and 12V2 in this case, are nice and consistent and on par with what we would expect from a good quality unit.

Power Efficiency

Power efficiency is measured by calculating actual supplied wattage divided by the wattage drawn at the wall/plug, multiplied by 100 to give a percentage. We then compare that to the particular 80 Plus certification the company claims to see if it meets that. You can see the 80 Plus certifications below, we always test 230v power supplies.

Efficiency is pretty consistent on this unit, never dropping below 85% and that’s well above the 81% required for Bronze rating and just stepping on the toes of the 80 Plus Silver classification.

Power Factor Correction

Power Factor Correction is the ratio of the real power flowing to the load, to the apparent power in the circuit. The aim of PFC is to make the load circuitry that is power factor corrected appear purely resistive (apparent power equal to real power). In this case, the voltage and current are in phase and the reactive power consumption is zero. The closer the number to one the better as this allows the most efficient delivery of electrical power (Source – Wikipedia).

The PFC is pretty good overall, there’s a bit of a dip around 40%, not sure what happened there, but it’s still a good result and certainly nothing to worry about.