To learn how we measure ripple, please click here.
The following table includes the ripple levels we measured on the 750 GQ's rails. The limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V and 5VSB).
Besides lousy performance in the transient response tests, the ACRF topology is prone to high ripple as well. The ripple performance of this unit is a big step backwards for EVGA-branded PSUs in this wattage category. On top of that, the 750 GQ fails to keep the 3.3V rail in spec during the full load and CL2 tests. In addition, the 5V rail has high ripple, leading to a failure during the overload test. To be fair, this pushes the PSU beyond its limits, so we aren't going to deduct any performance points. The +12V ripple performance is much better, but we would like to see below 40mV of ripple on this rail.
Ripple Oscilloscope Screenshots
The following oscilloscope screenshots illustrate the AC ripple and noise registered on the main rails (+12V, 5V, 3.3V and 5VSB). The bigger the fluctuations on the screen, the bigger the ripple/noise. We set 0.01V/Div (each vertical division/box equals 0.01V) as the standard for all measurements.