Our testing methodology for PSUs is straightforward, using a multi-meter and high-precision wattmeter and power analyzer that we installed on the 12V+, 5V+, and 3.3V+ output rails. We used a high-precision wattmeter and power analyzer on two 12V+ cables - one on the 12V+ PCIe cable and one on the 12V+ peripherals cable. With this, we can compare if the 12V+ output for the PCIe cables and peripherals are the same particularly when the system is loaded. We also have a wattage and power meter for the entire system to monitor the total wattage pulled by the computer. The test computer's configuration is as follows below.



To load the system, we used a combination of the Unigine Heaven Extreme graphics benchmarking tool and the Intel XTU CPU stress testing tool. Both applications ran simultaneously for 10 minutes and delivered an entire system power load of 550~570 watts which is approximately 65% load for the PSU.

Aside from loading the GPU and CPU with workload, we also used a Lamptron FC5V3 fan controller and a 33mm-thick HF DC Brushless 120mm (Model JLFS12E12BS6) 12V 3.0A, rated for up to 7000 RPM. This fan can draw 20 watts of power at full speed. This setup is to pull power from the 12V+ peripheral cable since the Lamptron fan controller is powered by a 4-pin Molex connector.



Results
We observed a difference in voltage between the 12V+ on the PCIe cables and the 12V+ on the peripheral cables. On our testing, the 12V+ on the PCIe cables appears to be more powerful, ensuring it delivers above 12.0V at high workloads. Running Unigine Heaven Extreme and Intel XTU CPU stress test simultenously, the 12V+ reading on the PCIe cables drops from 12.19V to 12.08V.

Meanwhile, the powerful 7000 RPM fan drawing 20W pulls the 12V+ reading from 12.11V down to 12.01V which is still impressive. The 5V+ and 3.3V+ lines appear to be very stable even at 62% power load.

Voltage Regulation


Based on Intel regulation standards of ±5%, the LEADEX III GOLD UP ATX 3.1 passes with ease. However, Super Flower boasts the LEADEX III GOLD UP ATX 3.1 for having "voltage regulation within 0.5% to ensure stability, durability, and reliability to every system build.". This very tight 0.5% voltage regulation is not observed under 20% load. At 65% load (550~570W), 12V+ on the PCIe and peripheral cables has the tightest voltage regulation that's very close to the claimed 0.5% voltage regulation. This ensures stable power delivery to components that mainly use the 12V+ rail - namely the CPU and graphics cards.

The LEADEX III GOLD UP PSU's peak efficiency is around 50% power load. It appears that it is also at the power load range wherein voltage regulation is at its tightest.

Acoustics
It's difficult to isolate the noise from the PSU from the noise coming from the graphics card and CPU cooler. Hence, we tested the noise of the entire test unit which uses an open testbench setup in a typical room setup scenario and using the PSU's Mode I intelligent cooling. Putting the sound meter directly under the PSU where the fan is, it reads under 38 dBA at <20% load. At 50% load running Unigine Heaven Extreme, the sound meter reads 48 dBA but louder noise is coming from the triple-fan graphics card. Overall, the LEADEX III GOLD UP ATX 3.1 is the least of your worries when it comes to noise, particularly for gaming PC setups with a triple-fan graphics card and CPU cooler with multiple fans installed.