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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 and, at the same time, it applies less stress to the DC-DC converters that many system components utilize.
Results 1-8: Load Regulation
Load regulation is tight at 12V, satisfactory at 5V, not so tight at 3.3V, and quite loose at 5VSB.
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.
Results 9-12: Hold-Up Time
The hold-up time is long 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.
Results 13-14: Inrush Current
Inrush current isn't high with 115V input, and at normal levels 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 is low.
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 |
1 | 5.263A | 1.982A | 1.987A | 0.992A | 84.975 | 88.085% | 0 | <6.0 | 44.51°C | 0.949 |
12.041V | 5.046V | 3.322V | 5.041V | 96.469 | 40.01°C | 115.14V | ||||
2 | 11.554A | 2.975A | 2.985A | 1.197A | 170.060 | 90.999% | 0 | <6.0 | 44.80°C | 0.978 |
12.044V | 5.043V | 3.316V | 5.014V | 186.882 | 40.86°C | 115.14V | ||||
3 | 18.178A | 3.473A | 3.487A | 1.404A | 255.069 | 91.943% | 0 | <6.0 | 45.90°C | 0.988 |
12.048V | 5.041V | 3.313V | 4.987V | 277.421 | 41.48°C | 115.14V | ||||
4 | 24.808A | 3.972A | 3.990A | 1.613A | 340.087 | 92.043% | 589 | 6.3 | 41.58°C | 0.992 |
12.048V | 5.037V | 3.306V | 4.961V | 369.489 | 46.64°C | 115.13V | ||||
5 | 31.052A | 4.968A | 4.997A | 1.825A | 425.096 | 91.300% | 588 | 6.3 | 42.11°C | 0.995 |
12.063V | 5.034V | 3.303V | 4.932V | 465.606 | 47.78°C | 115.12V | ||||
6 | 37.281A | 5.964A | 6.003A | 2.000A | 509.411 | 90.794% | 875 | 19.0 | 42.64°C | 0.996 |
12.065V | 5.031V | 3.298V | 4.906V | 561.060 | 49.21°C | 115.12V | ||||
7 | 43.601A | 6.963A | 7.015A | 2.257A | 594.899 | 90.113% | 1263 | 31.3 | 43.07°C | 0.996 |
12.059V | 5.028V | 3.293V | 4.876V | 660.172 | 50.22°C | 115.11V | ||||
8 | 49.927A | 7.964A | 8.028A | 2.475A | 680.241 | 89.373% | 1796 | 41.1 | 43.77°C | 0.996 |
12.054V | 5.025V | 3.288V | 4.851V | 761.127 | 52.09°C | 115.11V | ||||
9 | 56.622A | 8.467A | 8.528A | 2.481A | 765.168 | 88.647% | 1800 | 41.1 | 44.82°C | 0.997 |
12.056V | 5.022V | 3.284V | 4.839V | 863.163 | 53.80°C | 115.11V | ||||
10 | 63.238A | 8.971A | 9.058A | 2.596A | 849.882 | 87.807% | 1803 | 41.1 | 45.76°C | 0.997 |
12.060V | 5.019V | 3.279V | 4.817V | 967.894 | 55.66°C | 115.11V | ||||
11 | 70.246A | 8.974A | 9.069A | 2.604A | 934.666 | 86.933% | 2161 | 46.0 | 46.63°C | 0.997 |
12.064V | 5.016V | 3.275V | 4.802V | 1075.154 | 57.32°C | 115.11V | ||||
CL1 | 0.102A | 12.001A | 12.000A | 0.000A | 101.174 | 84.167% | 584 | 6.1 | 41.92°C | 0.957 |
12.092V | 5.035V | 3.293V | 5.087V | 120.206 | 47.49°C | 115.14V | ||||
CL2 | 70.032A | 1.000A | 1.000A | 1.000A | 857.930 | 88.481% | 1800 | 41.1 | 45.17°C | 0.997 |
12.061V | 5.027V | 3.300V | 4.948V | 969.621 | 55.66°C | 115.11V |
The PSU can handle high operating temperatures while delivering full power (and even more). The fan's speed is either at zero or very low RPM, with up to 60% of the unit's max-rated-capacity load.
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]) | PF/AC Volts |
1 | 1.235A | 0.495A | 0.496A | 0.196A | 19.999 | 75.439% | 0 | <6.0 | 0.645 |
12.022V | 5.049V | 3.328V | 5.109V | 26.510 | 115.14V | ||||
2 | 2.468A | 0.991A | 0.993A | 0.393A | 39.990 | 83.311% | 0 | <6.0 | 0.837 |
12.027V | 5.048V | 3.326V | 5.091V | 48.001 | 115.14V | ||||
3 | 3.704A | 1.485A | 1.491A | 0.592A | 60.021 | 86.071% | 0 | <6.0 | 0.920 |
12.032V | 5.047V | 3.324V | 5.074V | 69.734 | 115.14V | ||||
4 | 4.933A | 1.982A | 1.985A | 0.791A | 79.974 | 88.216% | 0 | <6.0 | 0.949 |
12.037V | 5.046V | 3.322V | 5.056V | 90.657 | 115.14V |
The PSU achieves high efficiency in these tests.
2% or 10W Load Test
Intel plans on raising the ante at efficiency levels under ultra-light loads. So from July 2020, the ATX spec will require 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.
Test # | 12V | 5V | 3.3V | 5VSB | DC/AC (Watts) | Efficiency | Fan Speed (RPM) | PSU Noise (dB[A]) | PF/AC Volts |
1 | 1.249A | 0.215A | 0.215A | 0.045A | 17.073 | 73.495% | 0 | <6.0 | 0.593 |
12.043V | 5.049V | 3.328V | 5.119V | 23.230 | 115.14V |
With 2% load, the PSU scores higher than 70% efficiency.
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.
Results 15-18: Efficiency
Satisfactory efficiency with normal loads and very high levels with light and super-light loads. We would like to see high PF with 230V, though.
5VSB Efficiency
Test # | 5VSB | DC/AC (Watts) | Efficiency | PF/AC Volts |
1 | 0.100A | 0.512 | 75.740% | 0.076 |
5.119V | 0.676 | 115.13V | ||
2 | 0.250A | 1.278 | 79.975% | 0.161 |
5.110V | 1.598 | 115.12V | ||
3 | 0.550A | 2.801 | 81.165% | 0.269 |
5.091V | 3.451 | 115.12V | ||
4 | 1.000A | 5.062 | 81.435% | 0.346 |
5.062V | 6.216 | 115.12V | ||
5 | 1.500A | 7.542 | 81.010% | 0.388 |
5.027V | 9.310 | 115.12V | ||
6 | 2.500A | 12.399 | 78.272% | 0.433 |
4.960V | 15.841 | 115.12V |
Results 19-20: 5VSB Efficiency
The unit is equipped with an efficient 5VSB rail.
Power Consumption In Idle And Standby
Mode | 12V | 5V | 3.3V | 5VSB | Watts | PF/AC Volts |
Idle | 12.035V | 5.050V | 3.329V | 5.125V | 5.174 | 0.281 |
115.1V | ||||||
Standby | 0.056 | 0.006 | ||||
115.1V |
Results 21-22: Vampire Power
Vampire power is kept low.
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 is not so aggressive under high operating temperatures. If they could use a large fan, things would be better in this area since it wouldn't be necessary to reach high RPMs to achieve the required airflow.
The following results were obtained at 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit) ambient temperature.
At normal operating temperatures, the fan speed profile is way more relaxed compared to high ambient. In no case did the PSU's fan noise exceed 40 dBA.
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Current page: Load Regulation, Hold-Up Time, Inrush & Leakage Current, Efficiency and Noise
Prev Page Specifications and Part Analysis Next Page Protection Features, DC Power Sequencing, Cross-Load Tests and Infrared ImagesAris Mpitziopoulos is a contributing editor at Tom's Hardware, covering PSUs.