Efficiency

Using the efficiency results from the previous page, we plotted a chart showing the efficiency of the 500B at low loads and at loads equal to 20%-110% of the PSU's maximum-rated load.



The 500B places close to last with both low and normal loads. Its design and secondary side components apparently don't leave room for more efficiency.

Efficiency at Low Loads

The next tests measure the efficiency of the 500B 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-, 60-, 80-, and 100 W (for PSUs with a capacity of over 500 W ). This is important for settings where the PC is in idle mode with Power Saving turned on.

Efficiency isn't bad at low loads, but we have seen many units of similar capacity and Bronze efficiency perform better. That said, efficiency easily surpassed 80% in the last two tests, making this unit a good choice for mainstream and mid-level builds with low idle power consumption.

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 5VSB rail performed rather well for a mainstream unit. Efficiency was above the specified mark in all tests and hit almost 80%, which is a high percentage for this particular rail, during the last two 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).

Consumption in standby is very low and absolutely in line with the requirements of the ErP Lot 6 2013 directive.

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 40°C-46°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). The background noise inside the anechoic chamber was below 30 dBA during testing, and the results were obtained with the PSU operating at 40°C-46°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 in this case was between 28 and 30°C.



Operational noise is not low, even at lower loads. We think EVGA should use a quieter fan with this PSU, even if it would raise the price slightly.