Efficiency

Using the efficiency results from the previous page, we plotted a chart showing efficiency of the EMR1500EGT at low loads and at loads equal to 20-100% of the PSU's maximum rated load.



For a discussion of these results, see the text at the end of the previous page.

Efficiency at Low Loads

In the next tests, we measured the efficiency of the EMR1500EGT 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 500W of capacity). This is important for settings where the PC is in idle mode with power saving turned on.


At ultra-low loads efficiency is, as expected, not that great, but you can't call it bad either if you take into account the huge capacity of this unit. The unit breaks the 80% barrier with a 80 W load, and its efficiency skyrockets with loads above 80 W. Its fan's speed was kept low despite the 40°C ambient we maintained inside the hotbox during the above tests, making the PSU practically inaudible.

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 100mA of load, 60% or higher with 250mA of load, and 70% or higher with 1A 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.


At 5VSB, efficiency is very high for the standards of this rail. The last two sets also passed the 80% mark. Over 60% efficiency with only 0.1A of load is noteworthy.

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).


With 0.2 W of phantom power, the unit passes the ErP Lot 6 2013 requirements with flying colors - that means less of a carbon footprint.

Fan RPM & Delta Temperature

The following chart illustrates the cooling fan's speed (RPMs) and the delta difference between input and output temperature. The following results were obtained at 40°C - 45°C ambient.



The fan curve follows a linear path as the load and the ambient increases. Despite a statement by Enermax that the fan's maximum speed is 2000 RPMs, we measured 100 RPMs more at full load. Also, the Delta difference between input and output exhaust grills is quite big, proving that the fan is removing the heat out of the PSU's internals efficiently, and that the horizontal heatsinks don't block air movement.