Efficiency

Using the efficiency results from the previous page, we plotted a chart to show the N700's efficiency at low loads and at loads equal to 20%-100% of the PSU's maximum-rated load.



Only the Highpower platform of the SilentiumPC Supremo M1 managed to perform better than the N700 at low loads, and the latter easily took the lead with higher loads. Titanium units can provide a significant efficiency boost over other units, which the graphs above show. Their only problem so far is their significantly higher price as compared to other units, which unfortunately won't change anyone soon.

Efficiency at Low Loads

In the next tests, we measured the efficiency of the N700 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 sits idle with Power Saving turned on.

Efficiency with low loads is high overall. This PSU will save you lots of money in comparison to an older units, especially if you don't use your PC for resource-intensive tasks since the N700 is incredibly efficient at low loads and in idle.

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 fully satisfied us with its performance and its high efficiency of almost 82% at full load.

Power Consumption in Idle & Standby

In the table below are the power consumption and voltage values of all rails (except -12V) while the PSU sits idle (powered on but without a load on its rails) and the PSU's power consumption in standby (without any load at 5VSB).

Andyson states the N700 to consume no more than 0.25 W power in standby, which was exactly the case here.

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 36°C-45°C ambient.



A chart that shows the cooling fan's speed (RPMs) and output noise follows. We measure the fan's noise output at a distance of one meter, 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 36°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.



The N700 is almost inaudible with light loads at temperature typical to those inside a PC chassis, but most users will object to the amount of noise it emits with high loads.