Efficiency

Using the efficiency results from the previous page, we plotted a chart showing the efficiency of the V850 at low loads and at loads equal to 20%-110% of the PSU's maximum-rated load.



Efficiency at low loads is astonishingly high and loses only to the Platinum revision of the same platform. It retains the same pace and loses at normal loads, though only by a small margin to the AX860 based on the same platform with all the appropriate components for Platinum efficiency.

For a discussion of these results, see the paragraphs at the end of the previous page.

Efficiency at Low Loads

In the next tests, we measured the efficiency of the V850 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.


At low loads, efficiency is outstanding: The PSU surpassed 80% efficiency in all tests! Even with only 40 W load! This is an amazing achievement for a high-capacity PSU, even a Gold-certified unit. Seasonic's newer platform clearly sets the efficiency bar too high.

5VSB Efficiency

The ATX spec 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.


Efficiency of the 5VSB rail was much higher than the corresponding levels the ATX specs sets. Efficiency even surpassed the 80% mark at full load, which is quite rare on this rail.

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 when the PSU is in standby mode (without any load at 5VSB).


Vampire power was low and barely exceeded 0.2 W, so the unit 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). The background noise inside the anechoic chamber was below 30 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 entire operating range of the PSU. The same conditions of the above graph apply to our measurements, but the ambient was between 28°C and 30°C.



The PSU features a very silent operation and will then be a real joy to users that hate noisy PSUs (and noisy PC components in general).