Efficiency

Using the results we gathered so far, we plotted a chart showing the PSU's efficiency at low loads and loads ranging from 10 to 110 percent of the maximum-rated capacity.




The PSU does not make the 70% efficiency mark at 2% load the newest ATX specification sets forth. However, the Cooler Master MWE Bronze 750 W still achieves impressive efficiency at such a light load. As shown in the charts above, the Corsair CX750F also performs well in all other load regions.

10%–110% Load Testing

These tests reveal the PSU's load regulation and efficiency levels under high ambient temperatures. They also show how the fan speed profile behaves under tough operating conditions.


The PSU was able to deliver the full load and more at high operating temperatures. My only small complaint here is the APFC converter's performance, which should deliver closer to unity results.

Light Load Testing

In the following tests, we measure the PSU's efficiency at loads significantly lower than 10 percent of the maximum capacity, which is the lowest load the 80 PLUS standard measures. This is important for representing when a PC is idle with its power-saving features turned on.


Very high efficiency levels under light loads.

Ultra-light Load Testing

The applied load in this test is only 10 W for PSUs with 500 W and less capacity. We dial in 2% of the maximum-rated capacity for all other PSUs. We only run this test with 115 V input.


At 2% load, the PSU cannot surpass 70% efficiency.

5VSB Efficiency

The 5VSB rail registers efficiency levels that are high enough.

Power Consumption in Idle and Standby

Vampire power with 230 V input stays below 0.1 W. It is even lower with 115 V.