Efficiency

Using the efficiency results from the previous page, we plotted a chart that shows the FTX-800-2's efficiency at low loads and at loads equal to 20% -100% of the PSU's maximum-rated load.



The FTX-800-2 manages to beat the SuperNOVA 850 T2 at light loads and takes second place in our graph at normal loads. However, we have to remind you that the 850 T2 has a much longer hold-up time that is inline with the ATX specification's requirements, while the FTX-800-2 definitely failed all of our hold-up time tests. We put an emphasis on these tests since they significantly impact a PSU's efficiency. You see, the higher the bulk caps' capacity, the larger the impact on efficiency since the caps need larger pulses of current to keep their charge, which results increases energy losses.

Efficiency at Low Loads

We measure the FTX-800-2's efficiency at loads much lower than 20% of its maximum-rated load (the lowest load the 80 Plus Standard measures) in these tests. The loads we dial are 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 you can see in the table above, efficiency is very high with light loads. The only downside here is the fan's speed as it exceeds 1000 RPM in the last two tests despite the very low load.

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 decently, but we would have liked higher overall efficiency. There should at least be a reading above the 80% mark.

Power Consumption in Idle & Standby

In the table below, you will find the power consumption and voltage values of all rails (except -12V) while the PSU idles (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 is very low because of the dedicated standby PWM controller and CM6502S APFC controller.

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 34-46 °C ambient.



A chart that shows the cooling fan's speed (RPMs) and its output noise follows. We measure the fan's noise from one 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 an ambient of 34-46 °C.



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 fan will be inaudible at a load of up to around 400 W under normal operating conditions. It will crack 40 db(A) with a load over 560 W.



The fan profile is almost the same with 115V.