Efficiency, Temperatures And Noise
Efficiency
Using the results from the previous page, we plotted a chart showing the SF-1600F14HT's efficiency at low loads and at loads equal to 10 percent to 110 percent of the PSU's maximum rated capacity.
Without a doubt, the Leadex Titanium unit is our new efficiency king, taking the crown from Corsair's AX1500i, which remains the overall performance leader thanks to its sophisticated digital platform. The amazing fact here is that Super Flower's engineers managed to beat a digital platform using analog circuits, and this is something definitely worth mentioning.
Efficiency at Low Loads
In the next tests, we measure the efficiency of the SF-1600F14HT 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.
| Efficiency at Low Loads | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Test | 12V | 5V | 3.3V | 5VSB | Power DC/AC (W) | Efficiency (%) | Fan Speed (RPM) | Fan Noise (dB[A]) | PF/AC (V) |
| 1 | 1.211A | 0.491A | 0.482A | 0.196A | 19.66 | 66.04 | 0 | 0 | 0.783 |
| 12.049V | 5.048V | 3.310V | 5.070V | 29.77 | 115.2 | ||||
| 2 | 2.449A | 0.988A | 0.995A | 0.391A | 39.76 | 78.38 | 0 | 0 | 0.883 |
| 12.048V | 5.045V | 3.309V | 5.065V | 50.73 | 115.1 | ||||
| 3 | 3.689A | 1.475A | 1.510A | 0.591A | 59.86 | 83.36 | 0 | 0 | 0.920 |
| 12.046V | 5.042V | 3.307V | 5.060V | 71.81 | 115.0 | ||||
| 4 | 4.918A | 1.983A | 1.995A | 0.791A | 79.82 | 84.83 | 0 | 0 | 0.939 |
| 12.044V | 5.040V | 3.305V | 5.055V | 94.09 | 115.0 |
At low loads, efficiency is great and this unit proves that even high-capacity PSUs can be efficient under light-load situations without compromising performance under normal loads. In addition, the PSU finishes all of the low-load tests in a fanless mode, despite the high ambient temperature inside our hot box (35 °C).
5VSB Efficiency
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 at 100, 250 and 1000mA, and one under the highest load the 5VSB rail can handle.
| 5VSB Efficiency | ||||
|---|---|---|---|---|
| Test # | 5VSB | Power DC/AC (W) | Efficiency(%) | PF/AC (V) |
| 1 | 0.102A | 0.52 | 71.23 | 0.038 |
| 5.071V | 0.73 | 116.0 | ||
| 2 | 0.252A | 1.28 | 74.85 | 0.087 |
| 5.067V | 1.71 | 116.2 | ||
| 3 | 1.002A | 5.06 | 79.69 | 0.258 |
| 5.053V | 6.35 | 115.9 | ||
| 4 | 3.002A | 15.04 | 78.25 | 0.430 |
| 5.011V | 19.22 | 115.9 |
At 5VSB, the Leadex unit performs well, taking over third place in the corresponding chart, with significant distance from the two first PSUs.
Power Consumption in Idle And Standby
| Mode | 12V | 5V | 3.3V | 5VSB | Power (AC) | PF/AC Volts |
|---|---|---|---|---|---|---|
| Idle | 12.051V | 5.050V | 3.313V | 5.076V | 8.88W | 0.392 |
| 116.0V | ||||||
| Standby | 0.11W | 0.006 | ||||
| 116.0V |
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), along with the power consumption when the PSU is in standby mode (without any load at 5VSB).
Power consumption at standby is very low with 115VAC and 230VAC inputs.
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 35 °C to 49 °C ambient temperature.
During our hot-box tests, the fan spun at full speed with over 1400W loads, outputting very loud noise levels. However, judging from the delta difference of the input and output temperatures, the fan did a great job in removing heat from the unit's internals.
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 35 to 49 °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 °C.
With up to 600W load, the Leadex PSU operates in passive mode. Afterward, the fan engages for short periods at its lowest speed, where it still outputs noticeable noise before entering into passive mode three more times. We believe that Super Flower could easily use a lower-speed fan, although we agree that it is better to be on the safe side rather than risk damaging the PSU over time. The high-noise output region of this PSU begins with more than 1300W load at normal ambient temperatures. Realistically, nobody should expect a 1.6kW PSU to be quiet at such high loads.