Antec VP550P 550w PSU
Noise and Ripple
So what is noise and ripple? This is where there are minute voltage fluctuations on each of the main rails in any PSU. In a nutshell, the good ones have very little, the awful ones fluctuate a lot. According to our buddies at HardwareSecrets, 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 Antec’s own 83% rating. They don’t say at what ammount of load that is though. Most likely around 50%.
Since this PSU has 2 x 12v rails, one handling the 20+4pin, SATA, Molex and PCIe and the other handling the 8pin CPU power, there are two 12 ratings. 12v1 and 12v2. 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.
41.02mv peak fluctuation
54mv peak fluctuation
29.1mv peak fluctuation
22.6mv peak fluctuation