Efficiency, Temperature And Noise
Our efficiency testing procedure is detailed here.
Using the results from the previous page, we plotted a chart showing the AX1500i efficiency at low loads, and loads from 10 to 110 percent of the PSU's maximum-rated capacity.
The efficiency difference between 115V and 230V input is large, because this is a high-capacity unit. Hence, at very high loads, the increased amperage with 115V leads to high energy losses. The only PSU that manages to beat the AX1500i in this section is the Super Flower Leadex 1600 Titanium, which uses one of the best analog platforms available on the market today. So, it seems that analog designs can still outperform the high-end digital PSUs, at least in some critical areas.
Efficiency At Low Loads
In the following tests, we measure the efficiency of the AX1500i at loads significantly lower than 10 percent of the device's maximum capacity (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.
|Test #||12V||5V||3.3V||5VSB||Power (DC/AC)||Efficiency||Fan Speed||Fan Noise||PF/AC Volts|
|1||1.217A||0.502A||0.485A||0.200A||19.69W||58.15%||0 RPM||0 dBA||0.885|
|2||2.460A||0.999A||1.000A||0.400A||39.75W||74.66%||0 RPM||0 dBA||0.950|
|3||3.706A||1.496A||1.515A||0.599A||59.83W||83.43%||0 RPM||0 dBA||0.968|
|4||4.942A||2.004A||1.999A||0.803A||79.77W||85.78%||0 RPM||0 dBA||0.982|
With 20W load, efficiency was pretty low; however, in the next three tests it was much higher, and with 60W and 80W loads it easily passed the 80 percent mark.
Corsair Link Screenshots
Below you will find screenshots of the Corsair Link software, which we took during the light-load test sessions.
With 20W and 40W load, the readings of the Corsair Link software were much closer to the actual results as compared to the results with 60W and 80W load.
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 will take four measurements: one each at 100, 250 and 1000mA, and one with the full load the 5VSB rail can handle.
|Test #||5VSB||Power (DC/AC)||Efficiency||PF/AC Volts|
Although it is analog-controlled, the 5VSB rail is highly efficient, with two readings exceeding the 80 percent mark, which is typically pretty hard for this rail to achieve.
Power Consumption In Idle And Standby
|Mode||12V||5V||3.3V||5VSB||Power (AC)||PF/AC Volts|
In the table above, you'll find the power consumption and voltage values of all rails (except -12V) when the PSU is idle (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).
This is the first time that we tested a PSU with lower power consumption at idle with 230V rather than with 115V. All the other PSUs we have tested so far had lower vampire power with 115V input.
Fan RPM, Delta Temperature And Output Noise
Our mixed noise testing is described in detail here.
The first chart below illustrates the cooling fan's speed (RPMs), and the delta between input and output temperature. The results were obtained at 38 C (100.4 F) to 49 C (120.2 F) ambient temperature.
The 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 18 dB(A) during testing, and the results were obtained with the PSU operating at 38 C (100.4 F) to 49 C (120.2 F) ambient temperature.
The following graphs illustrate the fan's output noise and speed 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 at 28 C (82.4 F) to 30 C (86 F).
This is a very quietly operating PSU, which is amazing, considering its huge capacity. Up to around 1.2 kW of load, the unit's noise stays below 40 dBA, and at low to mid loads it is below 25 dBA, making the PSU almost inaudible in this operational range.