The PSU worked under a load of 615W continuously without problems. Together with an APC SmartUPS SC 620 the power supply worked at loads up to 375W (from the mains) and 330W (from the batteries). There were no problems when the UPS switched to the batteries.
The output voltage ripple is only half of the permissible maximums. There is no low-frequency ripple at all.
The output voltages boast excellent stability. The +12V differs from the nominal value by no more than 2%. The +5V keeps within a 3% deflection. The PSU proves the high specified load capacity of the +5V and +3.3V rails in practice: it can yield 170W across these rails while keeping every voltage within the permissible limits. This is a perfect implementation of dedicated voltage regulation.
The PSU is 80% efficient at loads from 100W to maximum, reaching 86% at the peak. This is not a record-breaking but good result even for a modern PSU. The power factor is increasing along with load, reaching 0.99 at the maximum.
The fan is rotating at 900rpm at loads below 350W, i.e. over half of the full load, and is nearly silent then. Its speed grows up linearly afterwards, reaching 1600rpm at max load. Thus, the HPU-4M630-PE is quieter than most other PSUs.
I did not measure the temperature of the outgoing air due to the specific design of the front panel (it has a blank top and a mains connector in the center) as the thermometer would have been in the cord’s way, producing inadequate readings. Anyway, I didn’t note any sign of overheat.
Summing everything up, this model is a good one. It proves that Hiper was right in changing its supplier. The PSU is stable, powerful and quiet and has all the connectors you may need. I just can’t even think of any improvements to request from the maker. This model meets its specifications as well as consumer expectations from a PSU of this class. It might have detachable cables, but it would be a different model then.
I want to note the fact that the HPU-4M630 works well under high loads on the +5V and +3.3V rails. If you need a power supply for an old computer with an advanced CPU and multiple hard drives that is powered mostly by these rails (newer computers have transitioned to +12V), the Hiper HPU-4M630-PE will do the job. But you’ll have to use a 24→20-pin adapter or cut the extra part of the 24-pin connector off in order to power your mainboard because the mainboard connector of Hiper’s PSUs is non-splittable.