The PSU worked without problems at loads from 20W through 625W. Together with an APC SmartUPS SC 620 this power supply worked at loads up to 365W and 340W when powered by the mains and the batteries, respectively. The pair switched to the batteries normally, the UPS was stable.
The high-frequency output voltage ripple is far below the permissible maximum and nearly nonexistent on the +3.3V rail.
Besides the high-frequency ripple, there is low-frequency pulsation of a strange form. Anyway, the PSU keeps within the required limits even if you count this pulsation in.
The three main voltages boast superb stability. It is only at nearly-maximum loads that there is a 3% deflection from the nominal values.
The PSU is very efficient indeed. Its efficiency is over 80% even at a load of 50W! It is 87% efficient at the peak and 84% efficient at full load.
As for noisiness, the fan started at about 500rpm. You can’t hear the fan at such a speed unless you put your ear close to it. The speed is constant at loads up to 250W and then grows up along with the load. The PSU remains very quiet until a speed of 1000-1100rpm (over 400W) and then you begin to hear the hiss of the airflow and the sound of the fan’s bearings. Anyway, the noise is within comfortable limits even at full load, when the fan is rotating at about 1700rpm.
Thus, the MODU82+ 625W is actually silent at low loads. You can’t hear its fan through the panels of the system case at 500rpm. Comparing this model with the 525W model from the same series we tested earlier, there is no notable difference between them in terms of noisiness. You can choose between the EMD525AWT and EMD625AWT basing on how much power your PC needs.
Summing it up, the MODU82+ 625W has confirmed the success of the new series of Enermax PSUs. These top-quality, stable and nearly silent PSUs offer all the necessary connectors and will suit not only a gaming system but also a HTPC or any other PC whose owner wants to have a quiet computer.