Efficiency, Temperatures And Noise
Using the results from the previous page, we plotted a chart showing the efficiency of the 1600 P2 at low loads and at loads equal to 10 percent to 105 percent of the PSU's maximum capacity.
The 1600 P2 is a highly efficient PSU even under light loads, which definitely aren't the favorite playground for such high-capacity units. With 115V input, the unit registers a higher average score in the low-load range (20-80W). However, with higher loads the situation turns in favor of 230V. Also, at both light and normal loads, the 1600 P2 easily takes the lead from its Gold-rated sibling (1600 G2). It loses only to the Titanium-rated Corsair AX1500i in 20 to 100 percent of its max-rated capacity load. If we take into account that the AX1500i is an almost fully digitally-controlled unit while the Super Flower platform is based on analog circuits, this is quite a feat. Who said that analog circuits don't have anything left to offer?
Efficiency at Low Loads
In the next tests, we measure the efficiency of the 1600 P2 at loads significantly lower than 10 percent of the device's maximum (the lowest load the 80 PLUS standard measures). The loads we dialed were 20, 40, 60 and 80W. This is important for representing when a PC is idle with power-saving features turned on.
|Efficiency at Low LevelsEVGA SuperNOVA 1600 P2|
|Test #||12V||5V||3.3V||5VSB||DC/AC Watts||Efficiency||Fan Speed (RPM)||Fan Noise (dB[A])||PF/AC Volts|
At only 20W, efficiency drops below 60 percent. In the remaining two tests, it climbs above 70 percent. However, only during the last test and under an 80W load does it manage to surpass the 80-percent mark. For a 1600W beast, it does well. Best of all, during the entire light-load test session, the PSU operated in fanless mode.
The ATX specification states that 5VSB standby supply efficiency should be as high as possible, recommending 50 percent or higher efficiency with 100mA of load, 60 percent or higher with 250mA of load and 70 percent or higher with 1A or more of load.
We took four measurements: one each at 100, 250 and 1000mA, and one with the full load the 5VSB rail can handle.
|5VSB EfficiencyEVGA SuperNOVA 1600 P2|
|Test#||5VSB||DC/AC Watts||Efficiency||PF/AC Volts|
In our opinion, the 5VSB circuit isn't worthy of this high-end platform. It is efficient enough for a mid-level PSU, but in a Platinum-rated model, we would like to see readings above 80 percent in the last two tests. On top of that, the SuperNOVA 1600 P2 deserves a stronger 5VSB rail with at least 4A of current output.
Power Consumption In Idle And Standby
|Idle / StandbyEVGA SuperNOVA 1600 P2|
|Standby||Row 3 - Cell 1||Row 3 - Cell 2||Row 3 - Cell 3||Row 3 - Cell 4||0.13||0.007|
In the table above, you find the power consumption and 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 is low using 115V and a little higher with 230V input. However, in both cases, the 1600 P2 easily meets the ErP Lot 6 2013 requirements.
Fan RPM, Delta Temperature And Output Noise
The following chart illustrates the cooling fan's speed (RPMs) and the delta between input and output temperature. The results were obtained at 38 to 45 degrees C ambient temperature.
This next chart shows the cooling fan's speed (RPMs) and output noise. We measured acoustics from one meter away, inside a small, custom-made anechoic chamber with internals completely covered in soundproofing material (be quiet! Noise Absorber kit). Background noise inside the anechoic chamber was below 20 dB(A) during testing, and the results were obtained with the PSU operating at 38 to 45 degrees C ambient temperature.
The following graph illustrates the fan's output noise over the entire operating range of the PSU. The same conditions of the above graph apply to our measurements, though the ambient temperature was between 28 and 30 degrees C.
As you can see from the graph above, at normal operating conditions the PSU "runs" in passive mode for a pretty long period. At around 550W, the fan engages at low speed. After it exhausts most of the waste heat it switches to passive mode again. Afterward, the fan spins at low RPM up to about 1500 W. And when things get really tough, it switches to a higher speed—around 1500 RPM, according to our tests. This unit manages to combine two attributes that usually don't get along: high power and quiet operation.