To learn more about our PSU tests and methodology, please check out How We Test Power Supply Units.
Primary Rails And 5VSB Load Regulation
The following charts show the main rails' voltage values recorded between a range of 40W up to the PSU's maximum specified load, along with the deviation (in percent). Tight regulation is an important consideration every time we review a power supply, because it facilitates constant voltage levels despite varying loads. Tight load regulation also, among other factors, improves the system’s stability, especially under overclocked conditions. At the same time, it applies less stress to the DC-DC converters that many system components utilize.
Load regulation is tight at 12V, satisfactory at 5V, and average at 5VSB. We would like to see a within 1% deviation at 3.3V.
Hold-Up Time
Put simply, hold-up time is the amount of time that the system can continue to run without shutting down or rebooting during a power interruption.
The hold-up time here is much longer than the 17ms we consider to be the bare minimum, and the power ok signal is accurate.
Inrush Current
Inrush current, or switch-on surge, refers to the maximum, instantaneous input current drawn by an electrical device when it is first turned on. A large enough inrush current can cause circuit breakers and fuses to trip. It can also damage switches, relays, and bridge rectifiers. As a result, the lower the inrush current of a PSU right as it is turned on, the better.
Inrush current is low with 115V input, but quite high with 230V.
Leakage Current
In layman's terms, leakage current is the unwanted transfer of energy from one circuit to another. In power supplies, it is the current flowing from the primary side to the ground or the chassis, which in the majority of cases is connected to the ground. For measuring leakage current, we use a GW Instek GPT-9904 electrical safety tester instrument.
The leakage current test is conducted at 110% of the DUT's rated voltage input (so for a 230-240V device, we should conduct the test with 253-264V input). The maximum acceptable limit of a leakage current is 3.5 mA and it is defined by the IEC-60950-1 regulation, ensuring that the current is low and will not harm any person coming in contact with the power supply's chassis.
Leakage current exceeds 2mA. Still, it is much lower than the limit (3.5mA).
10-110% Load Tests
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 increased operating temperatures.
Test | 12V | 5V | 3.3V | 5VSB | DC/AC (Watts) | Efficiency | Fan Speed (RPM) | PSU Noise (dB[A]) | Temps (In/Out) | PF/AC Volts |
10% | 6.435A | 1.994A | 1.981A | 0.987A | 100.008 | 85.027% | 0 | <6.0 | 43.88°C | 0.966 |
12.184V | 5.016V | 3.332V | 5.069V | 117.619 | 40.28°C | 115.19V | ||||
20% | 13.877A | 2.994A | 2.976A | 1.187A | 199.965 | 89.663% | 0 | <6.0 | 45.21°C | 0.975 |
12.183V | 5.011V | 3.327V | 5.056V | 223.02 | 40.87°C | 115.12V | ||||
30% | 21.705A | 3.495A | 3.475A | 1.388A | 300.019 | 91.053% | 0 | <6.0 | 46.26°C | 0.981 |
12.161V | 5.008V | 3.324V | 5.044V | 329.499 | 41.28°C | 115.12V | ||||
40% | 29.489A | 3.998A | 3.975A | 1.59A | 399.833 | 91.168% | 658 | 15.4 | 42.03°C | 0.986 |
12.161V | 5.004V | 3.321V | 5.033V | 438.569 | 47.54°C | 115.12V | ||||
50% | 36.953A | 5.003A | 4.979A | 1.793A | 499.539 | 90.681% | 1482 | 40.7 | 42.11°C | 0.988 |
12.151V | 4.998V | 3.314V | 5.02V | 550.873 | 48.25°C | 115.12V | ||||
60% | 44.482A | 6.011A | 5.985A | 1.997A | 600.074 | 90.268% | 1483 | 40.7 | 42.84°C | 0.989 |
12.146V | 4.992V | 3.308V | 5.008V | 664.768 | 49.91°C | 115.11V | ||||
70% | 51.940A | 7.021A | 6.994A | 2.203A | 699.815 | 89.67% | 1481 | 40.7 | 43.59°C | 0.99 |
12.143V | 4.986V | 3.303V | 4.994V | 780.436 | 51.39°C | 115.11V | ||||
80% | 59.447A | 8.003A | 8.005A | 2.308A | 799.741 | 89.015% | 1484 | 40.7 | 43.72°C | 0.991 |
12.145V | 4.982V | 3.298V | 4.985V | 898.431 | 52.28°C | 115.11V | ||||
90% | 67.297A | 8.539A | 8.498A | 2.412A | 899.666 | 88.163% | 1850 | 46.4 | 44.2°C | 0.992 |
12.143V | 4.978V | 3.295V | 4.975V | 1020.457 | 53.63°C | 115.1V | ||||
100% | 74.925A | 9.048A | 9.023A | 3.029A | 999.692 | 87.21% | 1850 | 46.4 | 45.71°C | 0.992 |
12.146V | 4.975V | 3.292V | 4.954V | 1146.311 | 55.76°C | 115.09V | ||||
110% | 82.480A | 10.062A | 10.133A | 3.034A | 1100.312 | 86.203% | 1853 | 46.5 | 46.93°C | 0.993 |
12.148V | 4.97V | 3.286V | 4.945V | 1276.423 | 57.76°C | 115.1V | ||||
CL1 | 0.115A | 15.088A | 15.106A | 0A | 126.316 | 81.409% | 1490 | 40.9 | 42.11°C | 0.982 |
12.208V | 4.991V | 3.283V | 5.069V | 155.163 | 48.64°C | 115.18V | ||||
CL2 | 0.115A | 25.112A | 0A | 0A | 126.4 | 79.477% | 1838 | 46.2 | 43.56°C | 0.98 |
12.197V | 4.978V | 3.33V | 5.082V | 159.04 | 50.64°C | 115.18V | ||||
CL3 | 0.115A | 0A | 25.342A | 0A | 83.897 | 72.862% | 1837 | 46.2 | 44.53°C | 0.964 |
12.186V | 5.017V | 3.256V | 5.067V | 115.144 | 52.52°C | 115.19V | ||||
CL4 | 82.450A | 0A | 0A | 0.001A | 1000.228 | 87.932% | 1847 | 46.4 | 45.63°C | 0.992 |
12.131V | 4.996V | 3.327V | 5.032V | 1137.5 | 54.51°C | 115.08V |
The passive operation lasts up to 30% load, and with 40% load, the PSU's fan spins at low RPM. In all other tests, the fan speed is high, and the same applies to noise output. Lastly, the PSU doesn't have a problem with high operating temperatures, even under overload conditions.
20-80W Load Tests
In the following tests, we measure the PSU's efficiency at loads significantly lower than 10% of its maximum capacity (the lowest load the 80 PLUS standard measures). This is important for representing when a PC is idle with power-saving features turned on.
Test | 12V | 5V | 3.3V | 5VSB | DC/AC (Watts) | Efficiency | Fan Speed (RPM) | PSU Noise (dB[A]) | Temps (In/Out) | PF/AC Volts |
10W | 1.222A | 0.498A | 0.494A | 0.196A | 20.004 | 76.442% | 0 | <6.0 | 39.37°C | 0.617 |
12.148V | 5.023V | 3.339V | 5.093V | 26.169 | 37.07°C | 115.2V | ||||
20W | 2.690A | 0.697A | 0.692A | 0.295A | 40.002 | 80.941% | 0 | <6.0 | 40.84°C | 0.833 |
12.151V | 5.022V | 3.338V | 5.089V | 49.428 | 38.08°C | 115.23V | ||||
30W | 4.148A | 0.897A | 0.89A | 0.393A | 60.001 | 79.783% | 0 | <6.0 | 41.28°C | 0.92 |
12.182V | 5.02V | 3.337V | 5.085V | 75.205 | 38.93°C | 115.2V | ||||
40W | 5.608A | 1.096A | 1.088A | 0.492A | 79.958 | 82.868% | 0 | <6.0 | 42.61°C | 0.952 |
12.185V | 5.018V | 3.336V | 5.082V | 96.488 | 39.62°C | 115.21V |
Burst mode operation boosts efficiency during the first two tests, but there is an efficiency drop with a 60W load. Efficiency increases again at 80W. All in all, this platform is highly efficient at light loads.
2% or 10W Load Test
From July 2020, the ATX spec requires 70% and higher efficiency with 115V input. The applied load is only 10W for PSUs with 500W and lower capacities, while for stronger units, we dial 2% of their max-rated capacity.
12V | 5V | 3.3V | Standby Rail | DC/AC (Watts) | Efficiency | Fan Speed (RPM) | PSU Noise (dB[A]) | Temps (In/Out) | PF/AC Volts |
1.464A | 0.264A | 0.264A | 0.053A | 20.253 | 77.006% | 0 | <6.0 | 31.25°C | 0.628 |
12.139V | 5.022V | 3.338V | 5.096V | 26.301 | 28.26°C | 115.19V |
At 2%, load efficiency is sky-high!
Efficiency & Power Factor
Next, we plotted a chart showing the PSU's efficiency at low loads, and loads from 10 to 110% of its maximum rated capacity. The higher a PSU’s efficiency, the less energy goes wasted, leading to a reduced carbon footprint and lower electricity bills. The same goes for Power Factor.
With normal loads, efficiency could be higher. Efficiency is satisfactory with light loads, though, and outstanding with super-light loads.
5VSB Efficiency
Test # | 5VSB | DC/AC (Watts) | Efficiency | PF/AC Volts |
---|---|---|---|---|
1 | 0.100A | 0.512 | 67.546% | 0.074 |
5.123V | 0.758 | 115.14V | ||
2 | 0.250A | 1.279 | 76.040% | 0.153 |
5.118V | 1.682 | 115.14V | ||
3 | 0.550A | 2.809 | 78.093% | 0.273 |
5.107V | 3.597 | 115.13V | ||
4 | 1.000A | 5.093 | 77.260% | 0.376 |
5.092V | 6.592 | 115.13V | ||
5 | 1.500A | 7.615 | 78.887% | 0.429 |
5.076V | 9.653 | 115.14V | ||
6 | 3.000A | 15.077 | 76.580% | 0.503 |
5.026V | 19.688 | 115.13V |
We would like to see a more efficient 5VSB rail.
Power Consumption In Idle And Standby
Mode | 12V | 5V | 3.3V | 5VSB | Watts | PF/AC Volts |
---|---|---|---|---|---|---|
Idle | 12.087V | 4.928V | 3.313V | 4.929V | 8.148 | 0.458 |
115.2V | ||||||
Standby | 0.172 | 0.017 | ||||
115.2V |
Vampire power is low with 115V but exceeds 0.1W with 230V. Still, it is much lower than the limit, 0.25W, but it would be nice to see a below 0.1W reading.
Fan RPM, Delta Temperature, And Output Noise
All results are obtained between an ambient temperature of 37 to 47 degrees Celsius (98.6 to 116.6 degrees Fahrenheit).
The fan speed profile gets highly aggressive at increased operating temperatures. The PCB is small for a 1000W PSU and densely populated, so the fan must rotate at high speeds to handle the heat load.
The following results were obtained at an ambient temperature of 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit).
The fan speed profile is quite loose at normal operating temperatures, keeping noise output in control. With up to 450W loads and with less than 80W on the minor rails, the PSU operates in passive mode if it is selected. The transition from 750W to higher loads could be smoother since the difference in noise output between moderate and high loads is vast.
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