Test Setup

All measurements are performed utilizing a custom designed and built load tester, called Faganas, which is able to stress PSUs up to 1800 Watts. 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 three electronic loads (Array 3711A, 300W), a Rigol 1052E oscilloscope and a CEM DT-8852 sound level meter. In the near future we plan to acquire six additional loads to complete our new test set up, which with the help of our custom built software will have the same capabilities with the, ultra expensive, Chroma ATEs. 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 60W to the maximum specified load, and the deviation (in percent), when compared with the voltage values at 60W load.

Efficiency Chart

In this chart you will find the efficiency of ZM1000-HP Plus at low loads and at loads equal to 20-100% of the 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 ZM1000-HP Plus. 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 the maximum load that our tester can apply to these rails, 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 high enough for the Silver certification of the PSU, although at 100% load we would like to see above 86% efficiency. Similar to its smaller brother PF readings are low and with 20% load the PSU does not meet the 80PLUS requirement for above 0.9 PF. However we should not forget that the PSU was tested at way higher ambient compared to only 23°C that 80PLUS uses. As you can see at CL2 test the 5V rail went slightly above the 5.25 limit that the ATX spec sets, but for only 0.002V above the limit you don't have to lose your sleep over it. Voltage regulation at +12V and 5V stays within 3% deviation (1.87% and 2.95% for +12V and 5V respectively). However at 3.3V voltage regulation is a little above the 5% mark, hitting 4.89%. The ZM850-HP Plus overall exhibited better voltage regulation. Finally the PSU indeed features OTP protection since after 100% load and CL2 tests it refused to start and we had to wait a little to cool down a bit in order to start again.

Efficiency at Low Loads

In the next tests, we measure the efficiency of ZM1000-HP Plus 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 (approximately) 40, 65 and 90W. This is important for scenarios in which a typical office PC is in idle with power saving turned on.


Efficiency at low loads is very low and even with 88W load cannot pass the 80% mark. If your system idles at <90W loads then another PSU might give you lower power consumption, unless you leave your system at idle for short periods only.

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).


The PSU is ErP Lot 6 compliant since vampire draw or phantom load is below the 1W mark.