Efficiency

Using the efficiency results from the previous page, we plotted a chart that shows the G2-1600's efficiency at low loads and loads equal to 20%-100% of the PSU's maximum-rated load.



The PSU didn't perform too well with incredibly low loads, but those who buy such a monster will probably not run their unit at such low loads over prolonged periods of time as it would be like buying a Ferrari and driving it at 30-40 km/h all day long. The PSU actually performed much better with normal loads, nearly achieving 92.5% average efficiency.

Efficiency at Low Loads

In the next tests, we measured the G2-1600'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 over 500 W of capacity). This is important for settings where the PC is in idle mode with Power Saving turned on.


As we already wrote, efficiency with low loads wasn't high. To be frank, we expected this design to perform better at even such low loads, but SF must have tuned it for higher efficiency in the 20%-100% load range. The fan also spins at rather high speeds, which produces significant amounts of noise. We believe SF should use a slightly laxer fan profile with low loads.

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's load regulation is amazing, but we unfortunately can't say the same about its efficiency. We would also like it to deliver more power, with 20-25 W being ideal.

Power Consumption in Idle & 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 numbers when the PSU is in standby mode (without any load at 5VSB).


Phantom power is very low and easily meets ErP Lot 6 2013 requirements.

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 38°C-45°C ambient.



A chart that shows the cooling fan's speed (RPMs) and the output noise follows. We measure the fan's noise from 1 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 38°C-45°C ambient.



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.



Overall, this is a noisy PSU. SF obviously meant to be on the safe side by mostly focusing on reliability, not a quiet operation. If you want a silent high-capacity PSU, you had better look elsewhere.