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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 is much longer than what the ATX spec requires (17ms). Moreover, 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.
The inrush current is at normal levels.
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 | 2.346A | 1.978A | 1.974A | 0.977A | 49.753 | 83.262% | 0 | <6.0 | 44.94°C | 0.935 |
11.994V | 5.060V | 3.345V | 5.121V | 59.755 | 40.24°C | 115.18V | ||||
2 | 5.744A | 2.969A | 2.963A | 1.174A | 99.854 | 87.955% | 0 | <6.0 | 45.63°C | 0.973 |
12.002V | 5.056V | 3.342V | 5.112V | 113.529 | 40.50°C | 115.17V | ||||
3 | 9.475A | 3.465A | 3.441A | 1.372A | 149.746 | 88.980% | 893 | 20.7 | 41.02°C | 0.981 |
12.005V | 5.052V | 3.340V | 5.103V | 168.291 | 46.67°C | 115.17V | ||||
4 | 13.209A | 3.964A | 3.956A | 1.571A | 199.773 | 89.580% | 903 | 20.9 | 41.57°C | 0.982 |
12.004V | 5.048V | 3.337V | 5.093V | 223.010 | 47.59°C | 115.17V | ||||
5 | 16.606A | 4.958A | 4.947A | 1.771A | 249.869 | 89.513% | 977 | 23.2 | 42.16°C | 0.985 |
12.005V | 5.045V | 3.335V | 5.084V | 279.144 | 48.45°C | 115.16V | ||||
6 | 20.002A | 5.952A | 5.940A | 1.972A | 299.950 | 89.011% | 1349 | 32.5 | 42.77°C | 0.984 |
12.006V | 5.041V | 3.333V | 5.073V | 336.981 | 49.73°C | 115.16V | ||||
7 | 23.401A | 6.949A | 6.934A | 2.173A | 350.083 | 88.469% | 1667 | 39.0 | 43.27°C | 0.983 |
12.007V | 5.038V | 3.331V | 5.063V | 395.713 | 51.22°C | 115.16V | ||||
8 | 26.796A | 7.946A | 7.930A | 2.376A | 400.203 | 87.883% | 1863 | 42.3 | 43.72°C | 0.983 |
12.009V | 5.035V | 3.329V | 5.052V | 455.381 | 52.70°C | 115.15V | ||||
9 | 30.591A | 8.448A | 8.416A | 2.379A | 449.911 | 87.454% | 2009 | 44.4 | 44.73°C | 0.984 |
12.010V | 5.032V | 3.327V | 5.045V | 514.457 | 54.10°C | 115.14V | ||||
10 | 34.153A | 8.950A | 8.933A | 2.983A | 499.925 | 86.859% | 2070 | 46.4 | 45.11°C | 0.986 |
12.011V | 5.029V | 3.325V | 5.029V | 575.557 | 55.25°C | 115.14V | ||||
11 | 38.308A | 8.953A | 8.935A | 2.987A | 549.952 | 86.293% | 2082 | 46.7 | 46.20°C | 0.987 |
12.014V | 5.028V | 3.324V | 5.023V | 637.309 | 56.84°C | 115.14V | ||||
CL1 | 0.150A | 12.001A | 12.001A | 0.000A | 102.203 | 83.351% | 1260 | 31.4 | 43.82°C | 0.974 |
12.016V | 5.036V | 3.330V | 5.112V | 122.617 | 50.54°C | 115.17V | ||||
CL2 | 41.016A | 1.005A | 1.000A | 1.000A | 506.168 | 87.795% | 2079 | 46.6 | 45.21°C | 0.986 |
12.012V | 5.047V | 3.338V | 5.074V | 576.532 | 55.63°C | 115.13V |
During the first two tests, the PSU's fan is inactive, while afterward, it starts spinning at low speeds till the sixth test. The unit's efficiency is satisfactory, despite the high operating temperatures. Still, the APFC converter's performance could be improved since, even at high loads, the PF readings are not as close to unity as in other, similar spec products.
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 | 1.216A | 0.493A | 0.478A | 0.195A | 19.668 | 73.564% | 0 | <6.0 | 0.800 |
11.981V | 5.066V | 3.348V | 5.136V | 26.736 | 115.18V | ||||
2 | 2.483A | 0.990A | 0.984A | 0.390A | 40.071 | 82.432% | 0 | <6.0 | 0.919 |
11.988V | 5.062V | 3.346V | 5.132V | 48.611 | 115.18V | ||||
3 | 3.680A | 1.483A | 1.466A | 0.585A | 59.540 | 85.960% | 0 | <6.0 | 0.952 |
11.993V | 5.060V | 3.345V | 5.126V | 69.265 | 115.18V | ||||
4 | 4.948A | 1.979A | 1.973A | 0.781A | 79.966 | 87.174% | 0 | <6.0 | 0.963 |
11.997V | 5.058V | 3.343V | 5.121V | 91.731 | 115.18V |
The fan doesn't spin, at all, at light loads, even at high operating temperatures.
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 | 0.691A | 0.198A | 0.197A | 0.049A | 10.180 | 60.802% | 0 | <6.0 | 0.650 |
11.965V | 5.059V | 3.345V | 5.137V | 16.743 | 115.17V |
The PSU's efficiency isn't even close to 70%, which is what the ATX spec will require, according to our sources, at least, from 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 with light (20-80W) loads is fine, but this doesn't look to be the case with normal loads (10-100% of the PSU's max-rated capacity).
5VSB Efficiency
Test # | 5VSB | DC/AC (Watts) | Efficiency | PF/AC Volts |
1 | 0.100A | 0.514 | 73.534% | 0.112 |
5.139V | 0.699 | 115.17V | ||
2 | 0.250A | 1.285 | 76.126% | 0.225 |
5.136V | 1.688 | 115.17V | ||
3 | 0.550A | 2.823 | 77.194% | 0.337 |
5.132V | 3.657 | 115.16V | ||
4 | 1.000A | 5.126 | 76.990% | 0.405 |
5.125V | 6.658 | 115.16V | ||
5 | 1.500A | 7.678 | 77.462% | 0.440 |
5.118V | 9.912 | 115.15V | ||
6 | 3.000A | 15.273 | 75.751% | 0.485 |
5.091V | 20.162 | 115.15V |
The 5VSB rail's efficiency is not high enough to meet the Corsair competition.
Power Consumption In Idle and Standby
Mode | 12V | 5V | 3.3V | 5VSB | Watts | PF/AC Volts |
Idle | 12.025V | 5.059V | 3.344V | 5.138V | 5.068 | 0.484 |
115.2V | ||||||
Standby | Row 3 - Cell 1 | Row 3 - Cell 2 | Row 3 - Cell 3 | Row 3 - Cell 4 | 0.045 | 0.008 |
Row 4 - Cell 0 | Row 4 - Cell 1 | Row 4 - Cell 2 | Row 4 - Cell 3 | Row 4 - Cell 4 | 115.21V |
The vampire lower is low, with both voltage inputs.
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 profile is not as aggressive as it is in the 650W Ion SFX model.
The following results were obtained at 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit) ambient temperature.
The passive operating range has a weird shape, and it is not as large as we expected. With more than 330W load the PSU's fan exceeds 30 db(A) and with more than 375W it enters the 35-40 dB(A) range. The fan profile could be more relaxed, but Seasonic's engineers also had to make sure that the PSU will outlive the extra-long warranty.
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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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