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 the SS-1000XP 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 the SS-1000XP. 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.


Efficiency is outstanding! In seven out of the eight tests it is over 90% and it peaks at almost 93% with 40% load. This is an impressive result, without any doubt. At the same time voltage regulation is tight on all rails with +12V and 5V registering below 2% deviation and with 3.3V just a little over 2%. Also the unit proved that it can deliver its full power effortlessly at very high ambient, close to 50°C. Here we should note that the SS-1000XP, thanks to its high efficiency, has a very cool operation so it was really hard to raise the temperature inside the hot box. Even at full load we were forced to leave the heating element on for quite long, in order to keep the ambient high. Finally the fan at lower temperatures and low to middle loads is almost inaudible, but with high ambient/load and once it goes full speed it gets noisy. To give you an impression of the output noise level, we measured 48.1 dBA at 1m distance from the PSU while the fan was working with max RPMs.

Efficiency at Low Loads

In the next tests, we measure the efficiency of the SS-1000XP 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.


At low loads the unit, although it has 1kW capacity, registered high efficiency and at the last two tests it managed to surpass the 80% mark. This is very good performance for such a high capacity PSU while operating with minimal loads.

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.


Efficiency at 5VSB follows the general trend so it's way over the respective limits that ATX spec sets. With full load it easily passes 80% while voltage regulation remains at good levels, for the specific rail of course.

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 among the lowest we have ever seen and is only about one tenth of the limit that the ErP Lot6 2010 directive sets.