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Load Regulation, Hold-Up Time & 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 hold-up time we measure is long at 30ms, and the delay between the power-good signal and hold-up time is pretty large, ensuring the system's safe shut-down.
Inrush Current
For details on our inrush current testing, please click here.
With 115V input, the inrush current is quite low. It's a little higher than expected (but still fairly normal) with 230V input.
Load Regulation And Efficiency Measurements
The first set of tests reveals the stability of the voltage rails and the RM850x's efficiency. The applied load equals (approximately) 10 to 110 percent of the PSU's maximum load 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 compatible with Intel's C6/C7 sleep states 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 | PSU Noise | Temps (In/Out) | PF/AC Volts |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 5.196A | 1.982A | 1.982A | 0.996A | 84.561 | 86.551% | 0 RPM | <6.0 dB(A) | 46.18°C | 0.968 |
| 12.122V | 5.039V | 3.325V | 5.019V | 97.701 | 38.31°C | 115.16V | ||||
| 2 | 11.404A | 2.975A | 2.977A | 1.196A | 169.035 | 90.208% | 0 RPM | <6.0 dB(A) | 46.81°C | 0.988 |
| 12.115V | 5.037V | 3.323V | 5.015V | 187.383 | 38.43°C | 115.15V | ||||
| 3 | 18.022A | 3.473A | 3.460A | 1.397A | 254.172 | 91.172% | 0 RPM | <6.0 dB(A) | 47.26°C | 0.993 |
| 12.107V | 5.036V | 3.321V | 5.009V | 278.782 | 38.69°C | 115.03V | ||||
| 4 | 24.648A | 3.971A | 3.975A | 1.599A | 339.404 | 91.300% | 0 RPM | <6.0 dB(A) | 48.35°C | 0.995 |
| 12.099V | 5.035V | 3.319V | 5.004V | 371.745 | 38.99°C | 114.92V | ||||
| 5 | 30.951A | 4.966A | 4.971A | 1.800A | 424.710 | 91.024% | 0 RPM | <6.0 dB(A) | 49.07°C | 0.995 |
| 12.091V | 5.033V | 3.317V | 4.999V | 466.592 | 39.06°C | 114.89V | ||||
| 6 | 37.202A | 5.961A | 5.970A | 2.002A | 509.256 | 90.493% | 610 RPM | 10.2 dB(A) | 41.99°C | 0.996 |
| 12.082V | 5.032V | 3.314V | 4.995V | 562.759 | 57.90°C | 114.77V | ||||
| 7 | 43.522A | 6.957A | 6.970A | 2.204A | 594.564 | 89.918% | 655 RPM | 11.2 dB(A) | 42.50°C | 0.997 |
| 12.074V | 5.030V | 3.312V | 4.991V | 661.228 | 60.01°C | 114.74V | ||||
| 8 | 49.858A | 7.953A | 7.973A | 2.407A | 679.926 | 89.206% | 785 RPM | 18.1 dB(A) | 43.01°C | 0.997 |
| 12.065V | 5.029V | 3.310V | 4.987V | 762.198 | 61.87°C | 114.61V | ||||
| 9 | 56.596A | 8.457A | 8.462A | 2.407A | 764.885 | 88.453% | 943 RPM | 24.5 dB(A) | 44.22°C | 0.997 |
| 12.057V | 5.027V | 3.308V | 4.986V | 864.733 | 64.15°C | 114.47V | ||||
| 10 | 63.080A | 8.955A | 8.984A | 3.019A | 849.693 | 87.554% | 1154 RPM | 31.0 dB(A) | 45.81°C | 0.997 |
| 12.048V | 5.025V | 3.306V | 4.970V | 970.482 | 65.96°C | 114.44V | ||||
| 11 | 70.165A | 8.957A | 8.989A | 3.020A | 934.490 | 86.591% | 1415 RPM | 36.7 dB(A) | 47.43°C | 0.997 |
| 12.040V | 5.024V | 3.304V | 4.968V | 1079.195 | 69.43°C | 114.29V | ||||
| CL1 | 0.729A | 18.002A | 17.999A | 0.000A | 159.016 | 83.428% | 785 RPM | 18.1 dB(A) | 44.25°C | 0.989 |
| 12.095V | 5.029V | 3.315V | 5.068V | 190.603 | 61.86°C | 115.13V | ||||
| CL2 | 70.830A | 1.000A | 0.997A | 1.000A | 867.185 | 87.882% | 1119 RPM | 30.0 dB(A) | 45.60°C | 0.997 |
| 12.055V | 5.028V | 3.308V | 5.004V | 986.758 | 66.48°C | 114.42V |
Load regulation is pretty tight on all rails; everything except the 5VSB rail stays within 1% (and even then, 5VSB achieves 1.31% deviation, a new load regulation record for the 850W PSU category).
Efficiency-wise, the RM850x easily meets 80 PLUS' requirements for Gold certification, even under our hot box's very high ambient test conditions. Fan noise stays low not only because of its limited maximum speed, but also thanks to a relaxed profile. We have to push the PSU beyond its limits to make the fan spin at full speed, where it barely hits 37 dB(A).
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