Big thank you to CryoPC for providing the following test rig:
CPU: Core i5 750 @ 4GHZ
Motherboard: Asus P7P55D-E
GPU: Sapphire 5850 1GB
RAM: Corsair Dominator 4GB PC3-12800 DDR3
Storage: Samsung F3 500GB 16MB
CASE: NZXT Hades
Here at XSReviews, we don’t have the money for a full test bench when it comes to PSUs. Load testers cost thousands of pounds which unfortunately we just don’t have. Because of this, we don’t pretend to test the rail stability or efficiency of a PSU, as we simply can’t do it effectively.
However, what we can do is test the Ripple/Noise quality of each rail using an oscilloscope.
Noise and Ripple
So what is noise and ripple? This is the description of minute voltage fluctuations on each of the main rails in any PSU. In a nutshell, the good power supplies have very little, the awful ones fluctuate a lot. According to ATX Specifications, there shouldn’t be more than 120mv in peak to peak voltage fluctuation on the 12v rails, and no more than 50mv on the 5v and 3.3v rails.
If noise and ripple are present in abundance, you’re most likely going to find it at full load. Not posessing a load tester, the best I was able to do was to load up Furmark and S&M CPU stress and max out the test rig. This ended up drawing 375w from the mains. This will likely equate to nearly 20% less used by the PSU because no power supply is 100% efficient. All we have to go on here is the 80 PLUS broze rating of the PSU, which under 50% load conditions should be around 88%.
All images are of the average fluctuations, though numbers were observed for a few minutes at full load so the peak fluctuation is noted beneath each images. Not posessing a hot box to ensure that the unit is tested under stressfully heated conditions, air intakes and exhausts were partially covered. The internal temperature of the PSU was then measured using a probe, with results taken when it reached 40 degrees centigrade.
Since I used the .02v scale, each line on the graph represents 0.02v, or 20mv.
Peak to peak noise/ripple: 44.8mv
Peak to peak noise/ripple: 21.06mv
Peak to peak noise/ripple: 22mv
All perfectly fine results for noise/ripple. None of the rails stray outside of their safe zones so there shouldn’t be any problems with this PSU in that respect.