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.




Efficiency with 2% load is surprisingly high. It might not reach the 70% the newest ATX specification requires, but is very close. With 20–80 W load, overall efficiency is not that high, while the opposite is the case with 40–100 W load. Finally, in the 20%–100% load range, the Chieftronic unit performs pretty well.

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.


This platform has potential as it manages over 90.5% efficiency at full load under very tough conditions. I stressed it more in the 110% load test at 45.5 °C, and efficiency didn't drop below 90%. Regarding noise output, the fan starts at low speeds and is incredibly quiet at up to 50% load. It makes itself noticeable at 60% load and is set to run at close to full RPM with 80% load and higher.

Light Load Testing

In the following tests, we measure the PSU's efficiency at loads significantly lower than 10 percent of the maximum capacity (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.


There is no need for the fan to spin at such low 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.


Achieving close to 70% efficiency with 2% load is hard even with the power-hungry fan inactive. Don't expect very high efficiency in this load range with the unit's fan active (semi-passive mode toggled off).

5VSB Efficiency

Satisfactory results here, although I have seen more efficient 5VSB rails in other CWT implementations.

Power Consumption in Idle and Standby

Vampire power is low because the CM03X IC cuts off the APFC converter while the PSU is in standby mode.