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Load Regulation, Hold-Up Time, And Inrush Current
To learn more about our PSU tests and methodology, please check out How We Test Power Supply Units.
Primary Rails And 5VSB Load Regulation
Load Regulation testing is detailed here.
Hold-Up Time
Our hold-up time tests are described in detail here.
The 850W model's hold-up time is lower than Seasonic's Prime 650 W, but it still smokes the competition.
Inrush Current
For details on our inrush current testing, please click here.
The inrush current with 115V input is normal. But it's a little higher than expected with 230V.
Load Regulation And Efficiency Measurements
The first set of tests reveals the stability of the voltage rails and the PSU's efficiency. The applied load equals (approximately) 10 to 110 percent of the maximum load the supply can handle, in increments of 10 percentage points.
We conducted two additional tests. During the first, we stressed the two minor rails (5V and 3.3V) with a high load, while the load at +12V was only 0.1A. This test reveals whether a PSU is Haswell-ready or not. In the second test, we determined the maximum load the +12V rail could handle with minimal load on the minor rails.
| Test # | 12V | 5V | 3.3V | 5VSB | DC/AC (Watts) | Efficiency | Fan Speed | Fan Noise | Temps (In/Out) | PF/AC Volts |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 5.206A | 1.985A | 1.974A | 0.995A | 84.73 | 92.18% | 440 RPM | 20.7 dB(A) | 38.67°C | 0.968 |
| 12.130V | 5.041V | 3.341V | 5.005V | 91.92 | 41.04°C | 115.1V | ||||
| 2 | 11.444A | 2.970A | 2.961A | 1.200A | 169.61 | 93.87% | 440 RPM | 20.7 dB(A) | 38.86°C | 0.991 |
| 12.125V | 5.039V | 3.340V | 4.998V | 180.69 | 41.35°C | 115.1V | ||||
| 3 | 18.043A | 3.478A | 3.472A | 1.400A | 254.81 | 94.12% | 440 RPM | 20.7 dB(A) | 39.48°C | 0.996 |
| 12.122V | 5.036V | 3.338V | 4.990V | 270.73 | 42.51°C | 115.1V | ||||
| 4 | 24.629A | 3.974A | 3.954A | 1.605A | 339.70 | 93.67% | 440 RPM | 20.7 dB(A) | 40.60°C | 0.993 |
| 12.120V | 5.035V | 3.335V | 4.982V | 362.66 | 43.86°C | 115.1V | ||||
| 5 | 30.874A | 4.969A | 4.946A | 1.805A | 424.62 | 93.29% | 450 RPM | 21.0 dB(A) | 41.37°C | 0.992 |
| 12.118V | 5.034V | 3.334V | 4.975V | 455.15 | 44.18°C | 115.1V | ||||
| 6 | 37.126A | 5.961A | 5.939A | 2.009A | 509.58 | 92.71% | 530 RPM | 23.6 dB(A) | 42.15°C | 0.994 |
| 12.116V | 5.032V | 3.332V | 4.968V | 549.66 | 45.22°C | 115.1V | ||||
| 7 | 43.380A | 6.959A | 6.931A | 2.214A | 594.51 | 92.18% | 410 RPM | 19.5 dB(A) | 43.00°C | 0.995 |
| 12.112V | 5.032V | 3.332V | 4.960V | 644.94 | 47.34°C | 115.1V | ||||
| 8 | 49.638A | 7.949A | 7.922A | 2.420A | 679.48 | 91.49% | 520 RPM | 23.4 dB(A) | 44.40°C | 0.996 |
| 12.110V | 5.031V | 3.331V | 4.953V | 742.67 | 48.87°C | 115.1V | ||||
| 9 | 56.324A | 8.455A | 8.440A | 2.420A | 764.57 | 90.76% | 620 RPM | 27.6 dB(A) | 45.44°C | 0.997 |
| 12.108V | 5.029V | 3.329V | 4.950V | 842.42 | 50.37°C | 115.1V | ||||
| 10 | 62.760A | 8.957A | 8.927A | 3.042A | 849.30 | 90.08% | 975 RPM | 37.9 dB(A) | 46.64°C | 0.997 |
| 12.103V | 5.027V | 3.327V | 4.927V | 942.85 | 51.93°C | 115.1V | ||||
| 11 | 69.828A | 8.965A | 8.934A | 3.049A | 934.33 | 89.31% | 1305 RPM | 47.6 dB(A) | 46.84°C | 0.997 |
| 12.096V | 5.021V | 3.323V | 4.917V | 1046.21 | 52.68°C | 115.1V | ||||
| CL1 | 0.098A | 12.011A | 12.005A | 0.004A | 102.84 | 89.58% | 440 RPM | 20.7 dB(A) | 45.28°C | 0.980 |
| 12.139V | 5.082V | 3.381V | 5.089V | 114.80 | 50.51°C | 115.2V | ||||
| CL2 | 69.946A | 1.003A | 1.003A | 1.001A | 859.43 | 90.33% | 975 RPM | 37.9 dB(A) | 46.44°C | 0.997 |
| 12.097V | 4.997V | 3.300V | 4.964V | 951.44 | 52.04°C | 115.1V |
Load regulation is tight on all major rails, just like Seasonic promises. In addition, the output noise stays low despite the tough conditions we test under. It's only during the overload test, when we push the PSU beyond its official specs, that the noise reaches 48 dB(A).
Under 10% and 20% loads, this PSU easily meets the corresponding 80 PLUS Titanium levels. Although that's not the case with 50% load, we should stress that our tests are more taxing than the 80 PLUS organization's. Finally, under full load and despite the almost 47°C operating environment, Seasonic's SSR-850TD passes the 90% mark. It is also worth mentioning that the 94% efficiency level is met during the 30% load test. This is one of the most efficient PSUs we have evaluated so far.
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