Efficiency

Using the efficiency results from the previous page, we plotted a chart for the SS-1050XP3's efficiency at low loads and at loads equal to 20% -100% of its maximum-rated load.



The SS-1050XP3's performance with low loads was close to the average of its category. It performed much better with normal loads, doing nearly as well as some of the units at the very top of the chart.

Efficiency at Low Loads

These tests measure the efficiency of the SS-1050XP3 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 was high overall; however, we have seen Platinum units of similar capacity with significantly better efficiency levels at such loads. As you can see, fan noise also ramped up with even such low loads since we conducted our tests at an ambient of over 35°C.

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 performed well overall, though we would like it efficiency to at least be 80% at full load.

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).


0.17 W vampire power is a great result for even such a cutting-edge platform.

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 output at a distance of 1 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 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.



As you see in the graph above, this unit's passive mode doesn't last long at even close to normal room temperatures. Seasonic obviously meant to play it safe by tuning their hybrid mode around less heat than, say, Super Flower's implementations. We personally prefer Seasonic's approach since increased temperatures significantly reduce the longevity of such crucial components as electrolytic caps.