Efficiency

Using the efficiency results from the previous page, we plotted a chart showing efficiency of the ETL650AWT at low loads and at loads equal to 20-110% of the PSU's maximum-rated load.



Efficiency at low loads is pretty good and reaches the performance level of the Gold Silverstone ST65F-G unit. With normal loads, the NAXN ADV unit even leads the Bronze certified efficiency pack.

Efficiency at Low Loads

The next tests measure the efficiency of the ETL650AWT 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 a capacity over 500 W). This is important for settings where the PC is in idle mode with power saving turned on.


As we already mentioned, efficiency is very good at low loads: the unit surpassed the 80% efficiency mark easily in three out of four tests. Also, the fan kept its speed low despite the high ambient (around 35°C) at which we conducted the above tests.

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: one at 100, 250, and 1000 mA each, and one with the full load that the 5VSB rail can handle.


The performance of the 5VSB rail and, more specifically, its registered efficiency is, given the category of this unit, pretty good.

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).


The dedicated standby PWM controller ensures that phantom power stays below 0.5 W, which makes the PSU ErP Lot 6 2013 ready.

Fan RPM, Delta Temperature and Output Noise

The cooling fan's speed (RPMs) and the delta difference between input and output temperature are illustrated in the following chart. The following results were obtained at 38-45°C ambient.



A chart that shows the cooling fan's speed (RPMs) and the output noise follows. We measure the fan's noise from 1 meter away—inside a small custom-made anechoic chamber with internals that are completely covered in specialized soundproofing material (Be Quiet! Noise Absorber Kit) . Background noise inside the anechoic chamber was below 30 dBA during testing, and the results were obtained with the PSU operating at 38-45°C ambient.



The following graph illustrates the fan's output noise throughout the PSU's entire operating range. The same conditions of the above graph apply to our measurements, but the ambient in this case was between 28 and 30°C.



The fan's profile isn't too aggressive, but we think that a fan with less RPM would be a much better choice for this PSU.