XFX XTR 550 Fully Modular 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 is very good here, with very little deviance across various load scenarios. Some rails are around 1% out from spec, but this is well within safe tolerances and the results are reasonably consistent from 20% through to 100% loads.

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.

The 80 Plus Gold rating delivered right on its promise, delivering exactly what we would have expected across all loads.

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).

Being a Seasonic unit, I was expecting this result to be good and sure enough, it hasn’t disappointed one bit, this as good as any PSU I’ve ever tested has done, a very good result.