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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.
The load regulation is tight on all rails.
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 exceeds 17ms and the power ok signal is accurate, so we are fully satisfied.
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.
The inrush current is low with 115V input, and at normal levels with 230V.
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 | 5.244A | 1.986A | 2.006A | 0.993A | 84.735 | 87.638% | 0 | <6.0 | 43.69°C | 0.964 |
12.044V | 5.027V | 3.285V | 5.038V | 96.688 | 39.25°C | 115.10V | ||||
2 | 11.493A | 2.985A | 3.012A | 1.193A | 169.242 | 90.941% | 0 | <6.0 | 44.97°C | 0.980 |
12.038V | 5.024V | 3.284V | 5.030V | 186.101 | 40.05°C | 115.10V | ||||
3 | 18.151A | 3.483A | 3.502A | 1.394A | 254.364 | 91.712% | 0 | <6.0 | 45.80°C | 0.984 |
12.031V | 5.022V | 3.283V | 5.022V | 277.351 | 40.59°C | 115.09V | ||||
4 | 24.818A | 3.986A | 4.019A | 1.595A | 339.603 | 91.556% | 556 | 9.3 | 40.84°C | 0.979 |
12.024V | 5.019V | 3.281V | 5.015V | 370.925 | 46.45°C | 115.10V | ||||
5 | 31.153A | 4.985A | 5.030A | 1.798A | 424.900 | 91.107% | 556 | 9.3 | 41.43°C | 0.979 |
12.018V | 5.015V | 3.280V | 5.008V | 466.377 | 47.39°C | 115.10V | ||||
6 | 37.435A | 5.986A | 6.038A | 2.000A | 509.432 | 89.880% | 876 | 21.7 | 41.87°C | 0.981 |
12.011V | 5.013V | 3.278V | 5.000V | 566.791 | 48.36°C | 115.10V | ||||
7 | 43.791A | 6.987A | 7.047A | 2.204A | 594.760 | 89.216% | 1233 | 32.6 | 42.48°C | 0.983 |
12.004V | 5.010V | 3.276V | 4.992V | 666.649 | 49.69°C | 115.10V | ||||
8 | 50.150A | 7.991A | 8.062A | 2.408A | 680.101 | 88.458% | 1508 | 37.4 | 43.23°C | 0.984 |
11.998V | 5.006V | 3.274V | 4.985V | 768.842 | 51.36°C | 115.10V | ||||
9 | 56.922A | 8.495A | 8.553A | 2.409A | 765.057 | 87.784% | 1505 | 37.4 | 44.13°C | 0.986 |
11.991V | 5.004V | 3.273V | 4.982V | 871.522 | 52.81°C | 115.11V | ||||
10 | 63.432A | 8.999A | 9.076A | 3.022A | 849.871 | 86.839% | 1504 | 37.4 | 45.62°C | 0.987 |
11.984V | 5.001V | 3.272V | 4.964V | 978.671 | 54.93°C | 115.10V | ||||
11 | 70.536A | 9.000A | 9.078A | 3.024A | 934.656 | 85.988% | 1501 | 37.4 | 46.52°C | 0.988 |
11.979V | 5.000V | 3.272V | 4.961V | 1086.961 | 56.61°C | 115.11V | ||||
CL1 | 0.144A | 14.002A | 13.998A | 0.000A | 117.838 | 84.082% | 551 | 9.2 | 41.86°C | 0.974 |
12.033V | 5.016V | 3.277V | 5.051V | 140.147 | 47.39°C | 115.12V | ||||
CL2 | 70.842A | 1.002A | 0.997A | 1.000A | 862.779 | 87.415% | 1516 | 37.5 | 45.28°C | 0.987 |
11.991V | 5.013V | 3.280V | 5.019V | 986.989 | 54.20°C | 115.10V |
The PSU doesn't have a problem delivering full power (and more) at increased operating temperatures. The registered efficiency levels are satisfactory, but the PF readings should be closer to unity, especially at heavy loads.
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 | 1.187A | 0.496A | 0.486A | 0.198A | 19.387 | 69.492% | 0 | <6.0 | 0.791 |
12.041V | 5.029V | 3.287V | 5.062V | 27.898 | 115.10V | ||||
2 | 2.451A | 0.991A | 1.002A | 0.396A | 39.807 | 81.027% | 0 | <6.0 | 0.904 |
12.048V | 5.028V | 3.286V | 5.056V | 49.128 | 115.10V | ||||
3 | 3.648A | 1.490A | 1.489A | 0.594A | 59.330 | 85.242% | 0 | <6.0 | 0.945 |
12.047V | 5.027V | 3.286V | 5.050V | 69.602 | 115.10V | ||||
4 | 4.910A | 1.989A | 2.006A | 0.793A | 79.729 | 87.335% | 0 | <6.0 | 0.959 |
12.045V | 5.027V | 3.285V | 5.044V | 91.291 | 115.10V |
We would like to see higher than 70% efficiency with 20W load.
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 | 1.218A | 0.250A | 0.246A | 0.052A | 16.994 | 68.359% | 0 | <6.0 | 0.759 |
12.041V | 5.029V | 3.287V | 5.065V | 24.860 | 115.10V |
With 2%, of its max-rated-capacity, the power supply is efficient but it cannot reach the 70% threshold, that the ATX spec will require from July 2020.
Efficiency
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 efficiency levels are satisfactory under both normal and light loads.
5VSB Efficiency
Test # | 5VSB | DC/AC (Watts) | Efficiency | PF/AC Volts |
1 | 0.100A | 0.507 | 75.111% | 0.067 |
5.067V | 0.675 | 115.12V | ||
2 | 0.250A | 1.266 | 78.879% | 0.150 |
5.063V | 1.605 | 115.12V | ||
3 | 0.550A | 2.782 | 79.463% | 0.265 |
5.056V | 3.501 | 115.12V | ||
4 | 1.000A | 5.045 | 79.237% | 0.355 |
5.045V | 6.367 | 115.12V | ||
5 | 1.500A | 7.551 | 78.623% | 0.407 |
5.034V | 9.604 | 115.12V | ||
6 | 3.000A | 14.981 | 76.496% | 0.472 |
4.994V | 19.584 | 115.12V |
Results 19-20: 5VSB Efficiency
The 5VSB regulator circuit offers high efficiency.
Power Consumption In Idle And Standby
Mode | 12V | 5V | 3.3V | 5VSB | Watts | PF/AC Volts |
Idle | 12.058V | 5.027V | 3.285V | 5.068V | 5.113 | 0.308 |
115.1V | ||||||
Standby | Row 3 - Cell 1 | Row 3 - Cell 2 | Row 3 - Cell 3 | Row 3 - Cell 4 | 0.046 | 0.005 |
Row 4 - Cell 0 | Row 4 - Cell 1 | Row 4 - Cell 2 | Row 4 - Cell 3 | Row 4 - Cell 4 | 115.1V |
Results 21-22: Vampire Power
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 a bit aggressive under high operating temperatures, but this is necessary given that it controls a low-speed fan.
The following results were obtained at 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit) ambient temperature.
The passive operation lasts until the load exceeds 230W. Afterward, the fan spins at very low speeds. It takes more than 610W, to make the cooling fan output higher than 30 dB(A) noise.
MORE: Best Power Supplies
MORE: How We Test Power Supplies
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Current page: Load Regulation, Hold-Up Time, Inrush 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.
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