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.
XFX promised less than plus or minus 3% voltage deviance on each rail. We can see they actually stayed more or less within 1% voltage deviance on all rails which is an incredibly impressive achievement. The distribution of load onto a second virtual 12 volt rail at the end was done to stop the Chroma exceeding 50 amps on the 12 volt rail 1, you can find more details in the testing method page.
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.
As the graph demonstrates the XFX Pro 750W power supply meets the 80 Plus Gold standard quite comfortably doing much better than required at all levels of load. It is actually surprisingly close to Platinum certification with only the 50% load being about 2% lower than it needs to be while 100% and 20% load are almost spot on.
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 XFX Pro 750W Black Edition produced consistently high levels of PFC.
It looks like one of the very PSUs released by XFS.
And, hey it’s great to see proper PSU testing methods are being used while reviewing. 🙂
@Ryan: Another good review from you man!!
The test results and Editors Choice award are not surprising in the least considering it’s Seasonic unit but what amazes me is the price XFX sells it for. If you’re in the market for a PSU of this class the only thing you should be asking yourself is do you want surface or air shipping.
Nice work Ryan. It reminds me of the days I used to test & repair (yes, repair) PSU’s of all types. If I did it these days I’d demand danger pay.
I noticed you mentioned it missed 80plus Platinum by 2%, but you need to use the 115V Internal values, which means it did pass Platinum. Look on the 80plus site to clarify. This is a 115V internal power supply and not 230V.
i wonder if there is a way you can still find sun moon load tester used for cheap