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.
Measured hold-up time easily exceeds 17ms, and the power-good signal is also higher than 16ms. Moreover, that signal drops before the rails go out of spec.
Inrush Current
For details on our inrush current testing, please click here.
The inrush current is at normal levels with both voltage inputs.
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 0.10A. 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 RPM | Fan Noise dB(A) | Temps In/Out | PF/AC Volts |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 5.199A | 1.983A | 1.970A | 0.979A | 84.75 | 86.50% | 805 | 32.5 | 38.23 °C | 0.969 |
| 12.153V | 5.038V | 3.345V | 5.096V | 97.98 | 41.63 °C | 115.1V | ||||
| 2 | 11.429A | 2.968A | 2.960A | 1.176A | 169.62 | 90.03% | 805 | 32.5 | 38.85 °C | 0.992 |
| 12.145V | 5.036V | 3.341V | 5.086V | 188.40 | 42.53 °C | 115.1V | ||||
| 3 | 18.021A | 3.476A | 3.471A | 1.374A | 254.78 | 90.97% | 1070 | 35.8 | 39.52 °C | 0.980 |
| 12.137V | 5.034V | 3.339V | 5.074V | 280.08 | 43.51 °C | 115.1V | ||||
| 4 | 24.612A | 3.972A | 3.953A | 1.575A | 339.68 | 91.00% | 1475 | 47.7 | 41.15 °C | 0.982 |
| 12.129V | 5.034V | 3.336V | 5.065V | 373.26 | 45.64 °C | 115.1V | ||||
| 5 | 30.864A | 4.968A | 4.950A | 1.781A | 424.56 | 90.65% | 1915 | 51.1 | 41.81 °C | 0.986 |
| 12.120V | 5.031V | 3.332V | 5.054V | 468.33 | 47.13 °C | 115.1V | ||||
| 6 | 37.131A | 5.962A | 5.947A | 1.980A | 509.50 | 90.12% | 2140 | 52.1 | 42.95 °C | 0.988 |
| 12.112V | 5.031V | 3.328V | 5.042V | 565.38 | 48.50 °C | 115.1V | ||||
| 7 | 43.402A | 6.959A | 6.948A | 2.184A | 594.45 | 89.35% | 2205 | 52.8 | 44.28 °C | 0.990 |
| 12.105V | 5.029V | 3.323V | 5.029V | 665.34 | 50.77 °C | 115.1V | ||||
| 8 | 49.694A | 7.953A | 7.952A | 2.390A | 679.42 | 88.63% | 2205 | 52.8 | 45.34 °C | 0.991 |
| 12.095V | 5.028V | 3.319V | 5.018V | 766.55 | 52.38 °C | 115.1V | ||||
| 9 | 56.411A | 8.460A | 8.471A | 2.393A | 764.38 | 87.94% | 2205 | 52.8 | 46.33 °C | 0.991 |
| 12.086V | 5.026V | 3.316V | 5.010V | 869.19 | 54.83 °C | 115.1V | ||||
| 10 | 62.875A | 8.958A | 8.960A | 3.005A | 849.17 | 87.15% | 2205 | 52.8 | 47.18 °C | 0.992 |
| 12.079V | 5.025V | 3.314V | 4.990V | 974.42 | 56.36 °C | 115.1V | ||||
| 11 | 69.963A | 8.958A | 8.962A | 3.006A | 934.14 | 86.22% | 2205 | 52.8 | 48.93 °C | 0.992 |
| 12.070V | 5.024V | 3.314V | 4.984V | 1083.50 | 60.38 °C | 115.1V | ||||
| CL1 | 0.100A | 15.016A | 15.005A | 0.004A | 126.40 | 81.58% | 2205 | 52.8 | 46.36 °C | 0.987 |
| 12.170V | 5.033V | 3.305V | 5.100V | 154.95 | 52.80 °C | 115.1V | ||||
| CL2 | 70.807A | 1.002A | 1.003A | 1.002A | 867.52 | 87.57% | 2205 | 52.8 | 48.03 °C | 0.992 |
| 12.062V | 5.028V | 3.343V | 5.046V | 990.70 | 57.99 °C | 115.1V |
Load regulation is pretty tight on all rails (the 5V rail registers the smallest deviation). This Seasonic platform delivers good voltage stability, among others.
The XTR 850W achieves 90% efficiency with 20% load, while the 80 PLUS Gold certification asks for 87%. The 50% load test is a clear pass also, and under full load the PSU achieves 0.15% more efficiency than required. This unit's KM3S platform easily meets the Gold standard's requirements, even under stressful conditions. Moreover, the PSU can deliver its full load (and even more) at high ambient temperatures.
Of course, the cooling fan spins fast once the thermal load increases significantly, making a ton of noise. The fan profile gets aggressive once the ambient exceeds 40 °C, even under typical loads. If you need a silent PSU and you plan to push it hard, then you should look elsewhere.