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 CHY 502 thermometer, a Fluke 175 multimeter, and an Instek GPM-8212 power meter. Furthermore, in our setup, we included a wooden box, which, along with a heating element, was used as a hot box. Finally, we had at our disposal four more oscilloscopes (Rigol 1052E and VS5042, Stingray DS1M12, 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; we crank the heat inside the hotbox up to 45-50°C otherwise.

Voltage Regulation Charts

The following charts show the voltage values of the main rails, recorded over a range from 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 Silent Pro M2 850 W 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 Silent Pro M2 850 W. 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. 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 easily delivered its full power at over 50°C ambient, proving that Enhance should raise the 40°C operating limit. Efficiency throughout all load ranges is high and close to the efficiency levels that we usually get from Gold units. Voltage regulation, on all rails, is close to the average of the unit's category, so it's definitely not top notch, but you can't call it bad either. The fan was silent at lower loads. Only after 50% load test, with very high ambient, was it audible but not loud. All in all, the PSU registered a fairly good performance in these tests with the best aspects being efficiency and voltage regulation on the +12V rail.

Efficiency at Low Loads

In the next tests, we measured the efficiency of the Silent Pro M2 850 W 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 decent and doesn't, in any case, drop below 70%. Also, with an 80 W and a 100 W load, it manages to surpass the 80% mark, something notable for a Silver efficiency PSU with 850 W capacity.

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.


The 5VSB rail easily passed the respective limits that the ATX spec sets at all loads we dialed. All in all, the respective circuit is efficient enough, although we can't classify it among the most efficient we have ever seen, but we shouldn’t expect something mind blowing from a PSU of this category.

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 a little lower than the half of the ErP Lot 6 2010 limit - the PSU will also meet the future ErP Lot 6 2013 directive. This means less energy waste, lower electricity bills and, of course, a greener environment.