Test Setup

All measurements are performed utilizing ten electronic loads (seven Array 3711A, 300W each, and three Array 3710A, 150W each), which are able to deliver over 2500W of load and are controlled by a custom made software. We also use a Picoscope 3424 oscilloscope, a CHY 502 thermometer, a Fluke 175 multimeter and an Instek GPM-8212 power meter. Furthermore, in our setup we have included a wooden box, which along with a heating element is used as a Hot Box. Finally, we have at our disposal four more oscilloscopes (Rigol 1052E and VS5042, Stingray DS1M12 and a second Picoscope 3424) and a CEM DT-8852 sound level meter. In this article you will find more details about our equipment and the review methodology we follow. Finally, if the manufacturer states that the maximum operating temperature of the test unit is only 40°C then we try to stay near this temperature, otherwise we crank up the heat inside the hotbox up to 45-50°C.

Voltage Regulation Charts

The following charts show the voltage values of the main rails, recorded over a range from 60W to the maximum specified load, and the deviation (in percent) for the same load range.

5VSB Regulation Chart

The following chart shows how the 5VSB rail deals with the load we throw at it.

Efficiency Chart

In this chart you will find the efficiency of HCG-620M at low loads and at loads equal to 20-100% of PSU's maximum rated load.

Voltage Regulation and Efficiency Measurements

The first set of tests reveals the stability of voltage rails and the efficiency of HCG-620M. The applied load equals to (approximately) 20%, 40%, 50%, 60%, 80% and 100%, of the maximum load that the PSU can handle. In addition, we conduct two more tests. In the first we stress the two minor rails (5V & 3.3V) with a high load, while the load at +12V is only 2A and in the second test we dial the maximum load that +12V can handle while load at minor rails is minimal.


Antec's claims for up to 87% efficiency proved to be true, but with 230VAC power input. In general the PSU scores fairly high efficiency readings although at full load things get tough and it barely passes 83%. However we should take into account that we conducted the full load test at a super high operating temperature, which surely played a part in the significant efficiency drop. Voltage regulation at +12V is decent, at 5V a little over 3% and at 3.3V looser, reaching 4%. During above tests the fan started to make its presence felt once we reached test#3 and afterwards it was pretty loud since it operated at high RPMs, as you can also figure out by the large Delta values in temperature readings. Finally the Crossload test results are not so good and responsible for this is of course the group regulation design.

Efficiency at Low Loads

In the next tests, we measure the efficiency of HCG-620M at loads much lower than 20% of its maximum rated load (the lowest load that the 80 Plus Standard measures). The loads that we dial are 40, 60, 80 and 100W (for PSUs with over 500W capacity). This is important for scenarios in which a typical office PC is in idle with power saving turned on.


Efficiency at low loads is close to what we expected from a medium capacity, Bronze unit. Overall it's decent and in the last two tests it easily exceeds the 80% mark, making this PSU suitable for systems with low energy demands at idle.

5VSB Efficiency

ATX spec states that the 5VSB standby supply's efficiency should be as high as possible and recommends 50% or higher efficiency with 100mA load, 60% or higher with 250mA load and 70% or higher with 1A or more load.
We will take four measurements, three at 100 / 250 / 1000 mA and one with the full load that 5VSB rail can handle.


The 5VSB rail scored pretty high efficiency readings especially in the first three tests. At the last test, with full load, efficiency is good for this rail's standards however the difference to test#3 is marginal indicating that 2.5A are close to the limits for this unit's 5VSB rail.

Power Consumption in Idle & Standby

In the table below you will find the power consumption and the voltage values of all rails (except -12V), when the PSU is in idle mode (On but without any load at its rails) and the power consumption when the PSU is in standby (without any load at 5VSB).


Vampire power is extremely low, actually minimal, at 0.09W. The HCG-620M not only meets the ErP Lot 6 2010 requirements but most likely will meet all the future ones, at least for the next three to six years.