Efficiency

Using the efficiency results from the previous page, we plotted a chart that depicts the ERX430AWT's efficiency at low loads and loads equal to 20%-100% of the PSU's maximum-rated load.



The small Enermax unit's efficiency is average. It managed to surpass the affordable Seasonic S12G, but falls behind every other Gold-certified competitor (we didn't take into account the Gold-certified Silverstone unit since it adheres to the SFF format, which makes comparing it to an ATX unit unfair). The ERX430AWT performed well with low loads; however, it couldn't compete with the units which beat it in the normal loads graph. These tests really push the limitations of the ERX430AWT's older platform to the forefront.

Efficiency at Low Loads

The next tests measure the ERX430AWT's efficiency at loads much lower than 20% of its maximum-rated load (the lowest load the 80 Plus Standard measures). The loads we dialed were 40 W, 60 W, 80 W, 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.

As a unit with a low capacity, efficiency with low loads was high enough, but we have seen similar Gold-certified units perform notably better in these tests. This an affordable unit, not a high-end one, so we shouldn't be too hard on it. Yet we cannot help but be extra picky when it to matters surrounding efficiency.

5VSB Efficiency

The ATX specification states that 5VSB standby supply 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 the 5VSB rail can handle.

The 5VSB rail, efficient in the first two load tests, performed worse in the last two tests. While 78.5% efficiency, measured during the full-load test, is not low, we expect good platforms to crack the 80% mark in these tests.

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 was low, which is as it should in a modern PSU.

Fan RPM, Delta Temperature & 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°C-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 whose internals are completely covered in specialized soundproofing material (Be Quiet! Noise Absorber Kit). Background noise inside the anechoic chamber was below 20 dBA during testing, and the results were obtained with the PSU operating at 38°C-45°C ambient.



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



We believe Enermax could loosen the fan profile up a bit at normal operating temperatures. As it is, the fan profile doesn't help much in reducing output noise, so the ERX430AWT won't please noise-sensitive users.