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 Silent Pro M2 1000W 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 Silent Pro M2 1000W. 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 high, especially for the official efficiency rating that this unit carries which is mere 80 Plus Silver. Also we strongly believe that Enhance should stop stating that their PSUs' max operating temperature is restricted to 40°C, since lately all of their units we have tested proved exactly the opposite and didn't have any problem delivering their full power at much higher ambient temperatures. This is also the case with the M2 1000W, which worked flawlessly at CL2 test even at 47.6°C ambient. Regarding the fan's noise, with 80% load and high ambient it made its precense well felt however we wouldn't characterize it as annoyingly loud, since the noise it produced was a low frequency -but loud enough- hum. On the contrary with lower loads/ambient the fan was fairly quiet. Voltage regulation overall is not tight and especially at 3.3V it exceeds 4% deviation, while from the +12V rail we would like to see a deviation below 2%, ideally.

Efficiency at Low Loads

In the next tests, we measure the efficiency of Silent Pro M2 1000W 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, taking into account the 1kW capacity of this unit, we didn't expect great efficiency readings and unfortunately we were right, at least at 40W and 60W load tests. To be frank the efficiency reading with 40W load was a big dissapointment for us, since it went below 70% and we hate to see that. Thankfully with 100W load the PSU registered a fairly good 82.2% efficiency percentage.

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.


At 5VSB, efficiency starts at normal levels, with 0.1A load, at the second test goes sky high and at the last two tests it is at fairly good levels. As you can see with full load, at this rail, efficiency drops a little bit compared to the third test (1A load). This is an indication that 3A are close to the power limits of this rail. This is also suggested by the significant voltage drop at test#4.

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).


Cooler Master states that this unit is ErP Lot 6 2010 ready and the results clearly prove this. With only 0.28W vampire power the M2 1000W will not have any problem whatsoever meeting the future, stricter, ErP Lot 6 2013 requirements, which demand an under 0.5W energy consumption at standby.