Test Setup

All measurements were performed using ten electronic loads (seven Array 3711A [300 W each] and three Array 3710A [150 W each]), which are able to deliver over 2500 W of load and are controlled by a custom-made software. We also used a Picoscope 3424 oscilloscope, a Picoscope TC-08 thermocouple data logger, a Fluke 175 multimeter, and an Instek GPM-8212 power meter. We also included a wooden box, which, along with some heating elements, was used as a hot box. Finally, we had 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. We conduct all of our tests at 40 - 45°C ambient in order to simulate the environment seen inside a typical system with higher accuracy, with the 40 - 45°C being derived from a standard ambient assumption of 23°C and with 17 - 22°C added for the typical temperature rise within a system.

Voltage Regulation Charts

The following charts show the voltage values of the main rails, recorded over a range of 60 W 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 GreenMe 650 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 revealed the stability of the voltage rails and the efficiency of the GreenMe 650. The applied load was equal to (approximately) 20%, 40%, 50%, 60%, 80%, and 100% of the maximum load that the PSU can handle. In addition, we conducted two more tests. In the first test, we stressed the two minor rails (5V and 3.3V) with a high load while the load at +12V was only 2 A, and, in the second test, we dialed the maximum load that the +12V rail could handle while the load on the minor rails was minimal.


The PSU managed to achieve its full power flawlessly at 45°C ambient. Voltage regulation was also fairly good at +12V since it stayed within 2%, with average results on the minor rail. Efficiency surely looks low compared to more synchronous designs/PSUs but is decent for a Bronze unit. Regarding the cooling fan's output noise, It was audible up to 50% load and increased to a point some users with sensitive hearing might find annoying past 50% load. The fan's specifications led us to believe that it, to be frank, would be a lot quieter.

Efficiency at Low Loads

In the next tests, we measured the efficiency of the GreenMe 650 at loads much lower than 20% of its maximum rated load (the lowest load that the 80 Plus Standard measures). The loads that we dialed were 40, 60, 80, and 100 W (for PSUs with over 500 W of capacity). This is important for settings where the PC is in idle mode with power saving turned on.


At low loads, efficiency is fairly good for a Bronze unit. Efficiency manages to stay above 70%, even with a low 40 W load. The PSU even reaches and surpasses the 80% mark in Tests #3 and #4.

5VSB Efficiency

The 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 of load, 60% or higher with 250 mA of load, and 70% or higher with 1 A or more of load. We will take four measurements: three at 100, 250, and 1000 mA, and one with the full load that the 5VSB rail can handle.


Throughout all loads, efficiency at 5VSB surpasses the corresponding limits and peaks at nearly 78% with full load. A decent overall performance which meets our expectations.

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 (powered on but without any load on its rails) and the power consumption when the PSU is in standby mode (without any load at 5VSB).


Phantom power is really low in this unit and easily meets even the stricter ErP Lot 6 2013 requirements. Such low energy consumption in standby surely adds many "green points" to the GreenMe 650.