The PSU worked with an APC SmartUPS SC 620 at loads up to 335W. The switching to the batteries was performed normally.
I can also tell you that the PSU wouldn’t start up unless there was a load of 90W or higher on its +12V rail.
The high-frequency ripple of the output voltages is low even at full load: there is almost no pulsation on the +5V rail altogether. On the other two rails the pulsation is far smaller than the permissible maximums.
Besides the high-frequency ripple, the Galaxy DDX has a pulsation with a frequency of about 1.5 kHz. Like with the above-discussed Antec TruePower Quattro, the cause of this pulsation is unclear. Well, even so, it’s all right with the +12V and +5V rails while the +3.3V barely but meets the requirements to the output voltage ripple, too.
The +12V and +3.3V voltages are very stable but the +5V voltage is worse, sinking below the nominal value as the load grows up and even violates the permissible limit. However, this violation occurs when the combined load on the +5V and +3.3V rails is over 100 watts, which is unrealistic for a modern PC, which puts the biggest load on the +12V rail. So, the voltage regulation is overall good in the Galaxy DXX.
The main fan is a 135mm RL4T B1352512MB-3M from Globe Fan. Although the impeller is made from translucent plastic, the fan is not highlighted.
The main fan is accompanied with a 80mm SuperRed CHA8012DB-OA(E) from Cheng Home Electronic. Two different and differently oriented fans located close to each other often produce a rather annoying noise of air flow but this effect is barely perceivable in the Galaxy DDX because the fans are at a big distance from each other thanks to the large size of the housing.
The fan speed is almost constant at loads up to 600W and then begins to grow up. Although the 80mm fan is rotating at a lower speed than in the above-discussed Antec TruePower Quattro, the total amount of noise produced by the Enermax PSU is higher due to the second fan but the internal temperature is much lower. The difference between the input and output air temperature is just over 10°C even at full load.
Alas, the PSU is not very efficient. It can hardly meet the 80 Plus requirements as its efficiency is below 80% even in the 220V power grid.
The Enermax Galaxy DXX is overall a high-quality power supply for people who need to connect very, very many devices. It offers much more cables and connectors than most other available PSUs. On the downside are its very large size, not-very-high efficiency, and a noise level, which is low for a 1000W PSU but not really quiet. I think the PSU would be much better if the developer managed to increase its efficiency to 85% and get rid of the auxiliary 80mm fan.