Efficiency

Using the efficiency results from the previous page, we plotted a chart that shows the efficiency of the Dark Power P11-1000 at low loads and loads equal to 20% -100% of the PSU's maximum-rated load.



Efficiency is quite high and in line with the competition in this category.

Efficiency at Low Loads

These tests measure the Dark Power P11-1000'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 a capacity of over 500 W). This is important for settings where the PC is in idle mode with Power Saving turned on.

The PSU achieves over 80% efficiency in the last three tests with low loads and remains close to 78% with a load of 40 W. Given the unit's high capacity, it performed admirably in these tests.

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 isn't that efficient. We expected it to preform better in this test.

Power Consumption in Idle & Standby

You will find the voltage and power consumption values of all the rails (except -12V) while the PSU idles (powered on but without any load on its rails) in the table below, and the PSU's power consumption value when it is in standby mode (without any load at 5VSB).

At 0.12 W, phantom power is very low. However, it wasn't low enough to improve 5VSB efficiency in our light-load tests.

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 an ambient temperature of 38 °C-45 °C.



A chart that shows the cooling fan's speed (RPMs) and its output noise follows. We measure the fan's noise from a 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 an ambient temperature of 38 °C-45 °C.



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 temperature was in-between 28 °C and 30 °C.



As you can see in this graph, the PSU is very quiet at normal operating temperatures, and you won't hear its fan with typical loads. You will have to push this PSU beyond 750 W to make the fan spin faster, which will increase noise output to 40-43 dB(A).