Noise and Ripple can easily be measured by an oscilloscope. These show how much voltage fluctuation there is on a particular rail. We tested the rail stability of the 3.3 volt, 5 volt and 12 volt rails using an identical time and millivolt scale for all graphs.
The latest ATX 12 volt version 2.3 specifications state that ripple from peak to peak must be no higher than 50 millivolts for the 3.3 volt and 5 volt rails, while the 12 volt rail is allowed up to 120 millivolts peak to peak to stay within specifications.
| Load (%) | 3.3V Ripple | 5V Ripple | 12V Ripple |
| 20 |  |  |  |
| 40 |  |  |  |
| 60 |  |  |  |
| 80 |  |  |  |
| 100 |  |  |  |
As we can see the XFX Pro 750W Black Edition power supply had super tight regulation with very low noise and ripple across all rails. It was well within ATX specification and almost close to a total flat-line. In an ideal world there would be a totally flat-line with 0 millivolts of peak to peak ripple, the XFX unit wasn’t far off this.
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