Test Setup

All measurements were performed using ten electronic loads (seven Array 3711A [300 W each] and three Array 3710A [150 W each]), which are able to deliver over 2500 W of load and are controlled by a custom-made software. We also used a Picoscope 3424 oscilloscope, a CHY 502 thermometer, a Fluke 175 multimeter, and an Instek GPM-8212 power meter. Furthermore, in our setup, we included a wooden box, which, along with a heating element, was used as a hot box. Finally, we had at our disposal four more oscilloscopes (Rigol 1052E and VS5042, Stingray DS1M12, and a second Picoscope 3424) and a CEM DT-8852 sound level meter. In this article, you will find more details about our equipment and the review methodology we follow. Finally, if the manufacturer states that the maximum operating temperature of the test unit is only 40°C, then we try to stay near this temperature; otherwise, we crank up the heat inside the hot box up to 45-50°C.

Voltage Regulation Charts

The following charts show the voltage values of the main rails, recorded over a range from 60 W to the maximum specified load, and the deviation (in percent) for the same load range.

5VSB Regulation Chart

The following chart shows how the 5VSB rail deals with the load we throw at it.

Efficiency Chart

In this chart, you will find the efficiency of the TPX-1375M at low loads and at loads equal to 20-100% of the PSU’s maximum rated load.

Voltage Regulation and Efficiency Measurements

The first set of tests revealed the stability of the voltage rails and the efficiency of the TPX-1375M. The applied load was equal to (approximately) 20%, 40%, 50%, 60%, 80%, and 100% of the maximum load that the PSU can handle. In addition, we conducted two more tests. In the first test, we stressed the two minor rails (5 V and 3.3 V) with a high load, while the load at +12 V was only 2 A, and, in the second test, we dialed the maximum load that the +12 V rail could handle, while the load on the minor rails was minimal.


During the 20% load test, the PSU operated in fanless mode, despite the high operating temperature. The fan started spinning near the end of the 40% load test, and up to 60% load it was still very quiet. Afterwards, its speed increased along with the noise, but still it wasn't annoyingly loud.
As you can see from the full load and the CL2 tests, the TPX-1375M indeed can deliver its full power continuously even at 50°C, which is amazing, taking into account its monstrous capacity. On top of that, throughout all load range the PSU registered very high efficiency, close to the levels that we usually see on Platinum units, and voltage regulation was decent overall, with only the 3.3 V rail registering a little higher deviation than what we would like to see.

Efficiency at Low Loads

In the next tests, we measured the efficiency of the TPX-1375M at loads much lower than 20% of its maximum rated load (the lowest load that the 80 PLUS Standard measures). The loads that we dialed were 40, 60, 80, 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 we have expected from such a high-capacity PSU, efficiency at low loads is nothing to write home about, as it is mediocre. In the first two of four tests, efficiency dropped below 70%, and in the last two it didn't manage to pass the 80% mark. This is definitely not the right PSU for low loads, and I don't know how it could be since it has a capacity that reaches 1.4 kW.

5VSB Efficiency

The ATX spec states that the 5VSB standby supply's 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: three at 100, 250, and 1000 mA, and one with the full load that the 5VSB rail can handle.


Efficiency on the 5VSB rail is good overall, especially on the last two tests where it reached almost 80%. Also, this rail managed to keep a tight enough voltage regulation, taking also into account its high capacity.

Power Consumption in Idle & Standby

In the table below, you will find the power consumption and the voltage values of all rails (except -12 V) 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).


Phantom power is low in this beast and it barely exceeds one fifth of the ErP Lot 6 2010 limit.