Using the efficiency results from the previous page, we plotted a chart showing the efficiency of the AX1600i at low loads and at loads equal to 20%-100% of the PSU's maximum-rated load.
The AX1600i only fails to take the lead with light loads, which is mostly due to its high capacity. Under normal loads, the situations changes, with Corsair's flagship PSU achieving an astonishing 94.96% score.
Efficiency at Low Loads
In the next tests, we measured the efficiency of the AX1600i at loads much lower than 20% of its maximum-rated load (the lowest load the 80 Plus Standard measures). The loads we dialed in were 40 W, 60 W, 80 W, 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.
| Efficiency at Low Loads - Corsair AX1600i|
|Test #||12 V||5 V||3.3 V||5 VSB||Power|
|Efficiency||Fan Speed||PSU Noise||PF/AC |
|1||2.889A||0.499A||0.480A||0.201A||39.840W||79.781%||0 RPM||<6.0 dB(A)||0.752|
|2||4.118A||0.997A||0.995A||0.401A||59.816W||83.681%||0 RPM||<6.0 dB(A)||0.851|
|3||5.355A||1.494A||1.511A||0.601A||79.885W||85.738%||0 RPM||<6.0 dB(A)||0.904|
|4||6.589A||2.003A||1.992A||0.801A||99.856W||90.636%||0 RPM||<6.0 dB(A)||0.928|
This PSU does really well with light loads for its gargantuan 1.6 kW capacity. Efficiency is close to 80% with 40 W and exceeds 90% with 100 W!
Corsair Link Screenshots
Screenshots of the Corsair Link software follow. The order of these screenshots is the same as the order of the tests shown in the table above (low loads efficiency test #1 to test #4).
The ATX specification and CEC, ErP Lot 3 2014, and ErP Lot 6 2010/2013 state that 5VSB standby supply efficiency should be as high as possible, recommending, among others, 75 percent or higher efficiency with 550mA, 1A, and 1.5A of load. The PSU should also achieve more than 75% efficiency at 5VSB with its full load, or with 3A if its maximum current output on the rail is higher than 3A.
We will take six measurements: one at 100, 250, 550, 1000, and 1500 mA and another with the full load the 5VSB rail can handle.
| 5VSB Efficiency - Corsair AX1600i|
|Test #||5VSB||Power (DC/AC)||Efficiency||PF/AC Volts|
The 5VSB rail is incredibly efficient as well!
Power Consumption in Idle And 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).
| Idle / Standby - Corsair AX1600i -230V|
|Mode||12 V||5 V||3.3 V||5VSB||Power (AC)||PF/AC Volts|
Power consumption in standby is minimal, which is how this PSU achieves such high efficiency with light loads on the 5VSB rail.
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 38-47 °C ambient.
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 hemi-anechoic chamber. Background noise inside the hemi-anechoic chamber is below 6.0 dBA during testing, and the results are obtained with the PSU operating at ambient temperatures of 38-45 °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 30 °C and 32 °C
The last graph illustrates the fan's speed throughout the PSU's entire operating range. The same conditions as for the graph above apply.