Test Setup

All measurements are performed utilizing nine electronic loads (six Array 3711A, 300W each, and three Array 3710A, 150W each), which are able to deliver over 2000W of load and are controlled by a custom made software. We also use a DS1M12 (Stingray) 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 two more oscilloscopes (Rigol 1052E and VS5042) 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.

Voltage Regulation Charts

The following charts show the voltage values of the main rails, recorded over a range from 70W to the maximum specified load, and the deviation (in percent) for the same load range.

Efficiency Chart

In this chart you will find the efficiency of HCP-1200 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 HCP-1200. 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 minimum.


Efficiency is great, especially if we take into account that we have a 1200W PSU here and that as capacity goes up, it becomes harder to keep high efficiency. Voltage regulation at +12V was near 2%, at 5V close to 3% and at 3.3V a little over 5%, the current ATX limit. We don't know if the sample we had in our hands had the loose ATX connectors symptom but another HCP-1200 we had tested with the previous loader exhibited much better voltage regulation, not only at 3.3V but on all rails. Finally, although we operated the PSU at 52.1°C with full load it worked flawlessly and the most amazing of all was that its fan operated very quietly but efficiently. Antec's claims that the fan is very quiet are indeed true. We expected much more noise but thankfully we were wrong.

Efficiency at Low Loads

In the next tests, we measure the efficiency of HCP-1200 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, 70 and 100W. This is important for scenarios in which a typical office PC is in idle with power saving turned on.


Some of you might consider efficiency testing of a 1200 W PSU at such low loads a joke, since it makes little sense to buy a top performing Mega PSU and have it run with a system that draws only so little power. However we want to give you an idea of the efficiency at such low loads, because these numbers are significant for systems that idle a lot.
The 80% mark is only passed at 100W load. Except for the 69% reading in test #1, the HCP-1200 performs fairly well even at low loads, taking of course into account its huge capacity.

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 100 mA load, 60% or higher with 250 mA 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.



With only 0.1A at 5VSB, efficiency is a little lower than the 50% mark but in all other tests it is way higher than the levels that ATX spec recommends. Overall good performance here.

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).


Despite its enormous capacity, the HCP-1200 consumes very little power in standby, so it easily meets the ErP Lot 6 2010 requirements (and on the verge the future 2013 ones).