The +12V voltage has a large 5% zone, but this deflection can only be observed when there’s an unrealistically high load on the +5V and +3.3V rails. This voltage isn’t going to differ from the required level more than by 2 or 3% at typical loads.
The +5V voltage deflects from the default level when there is a very high load on the +5V rail or a very low load on the +12V rail. Anyway, each of our three reference configurations is in the 1% zone.
The +3.3V voltage seems to be the most stable as it deflects no more than by 3%, but the 1% zone doesn’t cover the weakest of our reference configurations.
So, the output voltages of the Antec HCG-520 are quite satisfactory.
Output Voltage Ripple
The high-frequency voltage ripple isn’t strong but there are spikes above the permissible limits on each power rail. Such spikes are regular on the +12V rail (at the moments of switching of the transistors) and occasional on the other rails.
The low-frequency ripple has fewer spikes. Moreover, the voltage spikes on the +3.3V rail do not violate the permissible limits.
Temperature and Noise
Like the original Seasonic, the Antec HCG-520 is cooled by an ADDA fan, but it’s the ADN512MB-A90 model now with more blades (11 instead of 7) and a larger diameter (135 instead of 120 millimeters).
The fan behaves like in the original Seasonic. Its speed is very low at loads up to 200 watts and then it suddenly accelerates to its maximum of 1900 RPM.
So, the PSU is almost silent at loads up to 200 watts, comfortable at loads up to 300 watts, and audible thereafter.
The Antec HCG-520 is overall comparable to the original Seasonic in terms of noisiness. The Antec has a lower maximum level of noise but gets noisy somewhat faster than the Seasonic.
Efficiency and Power Factor
The Antec HCG-520 is almost as efficient as the original Seasonic: close to 80% at 50 watts and over 85% at loads above 80 watts. That's an excellent result, so the PSU can proudly sport its 80+Bronze certification.
The power factor is high, just as you can expect from a modern PSU with active power factor correction.
The standby source doesn’t allow its voltage to deflect more than by 2%, the allowable deflection being 5%.
The Antec HCG-520 is similar to the Seasonic S12-II Bronze SS-520GB but has longer cables and a prettier exterior design. It may also turn out to be cheaper than the original Seasonic.