Why you can trust Tom's Hardware Our expert reviewers spend hours testing and comparing products and services so you can choose the best for you. Find out more about how we test.
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.
NZXT's hold-up time is 2ms longer than what the ATX specification requires, while the power-good signal is accurate (but lower than 16ms).
Inrush Current
For details on our inrush current testing, please click here.
Measured inrush current is on the high side, especially with 230V.
Load Regulation And Efficiency Measurements
The first set of tests reveals the stability of the voltage rails and the E850’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 | 5.262A | 1.988A | 1.972A | 0.981A | 84.912 (71) | 86.212% | 590 RPM | 10.4 dB(A) | 40.31°C | 0.975 |
| 12.031V | 5.032V | 3.347V | 5.099V | 98.492 | 47.19°C | 115.26V | ||||
| 2 | 11.513A | 2.983A | 2.960A | 1.179A | 169.409 (154) | 89.911% | 956 RPM | 24.4 dB(A) | 40.86°C | 0.985 |
| 12.030V | 5.031V | 3.345V | 5.088V | 188.418 | 48.24°C | 115.15V | ||||
| 3 | 18.165A | 3.481A | 3.439A | 1.379A | 254.492 (238) | 90.771% | 1245 RPM | 32.4 dB(A) | 41.07°C | 0.987 |
| 12.028V | 5.029V | 3.343V | 5.077V | 280.368 | 49.56°C | 115.14V | ||||
| 4 | 24.819A | 3.978A | 3.951A | 1.580A | 339.677 (321) | 90.748% | 1598 RPM | 37.4 dB(A) | 41.57°C | 0.988 |
| 12.026V | 5.028V | 3.341V | 5.065V | 374.308 | 50.46°C | 115.01V | ||||
| 5 | 31.147A | 4.976A | 4.939A | 1.781A | 424.992 (402) | 90.362% | 1907 RPM | 41.3 dB(A) | 42.18°C | 0.988 |
| 12.023V | 5.027V | 3.340V | 5.054V | 470.322 | 51.43°C | 114.89V | ||||
| 6 | 37.409A | 5.971A | 5.930A | 1.984A | 509.510 (485) | 89.840% | 2162 RPM | 43.9 dB(A) | 42.85°C | 0.988 |
| 12.021V | 5.027V | 3.338V | 5.043V | 567.130 | 52.73°C | 114.87V | ||||
| 7 | 43.740A | 6.967A | 6.922A | 2.188A | 594.815 (569) | 89.235% | 2162 RPM | 43.9 dB(A) | 43.26°C | 0.989 |
| 12.019V | 5.025V | 3.336V | 5.029V | 666.575 | 53.57°C | 114.75V | ||||
| 8 | 50.075A | 7.962A | 7.917A | 2.392A | 680.169 (651) | 88.573% | 2187 RPM | 43.9 dB(A) | 43.74°C | 0.990 |
| 12.017V | 5.025V | 3.335V | 5.019V | 767.918 | 54.46°C | 114.61V | ||||
| 9 | 56.805A | 8.462A | 8.399A | 2.395A | 765.087 (734) | 87.855% | 2171 RPM | 43.9 dB(A) | 44.40°C | 0.991 |
| 12.016V | 5.024V | 3.334V | 5.012V | 870.849 | 55.64°C | 114.58V | ||||
| 10 | 63.265A | 8.958A | 8.910A | 3.006A | 849.906 (814) | 86.874% | 2175 RPM | 43.9 dB(A) | 45.56°C | 0.991 |
| 12.016V | 5.025V | 3.333V | 4.991V | 978.321 | 57.81°C | 114.42V | ||||
| 11 | 70.319A | 8.962A | 8.913A | 3.010A | 934.678 (897) | 84.656% | 2179 RPM | 43.9 dB(A) | 46.80°C | 0.992 |
| 12.016V | 5.024V | 3.332V | 4.984V | 1104.089 | 59.83°C | 114.35V | ||||
| CL1 | 0.144A | 12.004A | 11.998A | 0.000A | 102.225 (110) | 83.899% | 1766 RPM | 39.7 dB(A) | 42.38°C | 0.983 |
| 12.052V | 5.030V | 3.343V | 5.110V | 121.843 | 51.96°C | 115.21V | ||||
| CL2 | 70.024A | 1.002A | 1.002A | 1.000A | 854.131 (828) | 87.398% | 2171 RPM | 43.9 dB(A) | 45.31°C | 0.991 |
| 12.006V | 5.027V | 3.336V | 5.043V | 977.292 | 57.61°C | 114.44V |
Load regulation is super tight, though it's merely decent at 5VSB. We're most disappointed in NZXT's aggressive fan profile, which results in lots of noise even though we chose Silent mode in the CAM software. If you want the E850 to be quiet under high temperatures, consider creating a custom fan profile instead.
The E850's efficiency is high, easily satisfying the 80 PLUS Gold specification's requirements with 20% and 50% load. Although it falls short under full load, we do test at much higher temperatures than the 80 PLUS organization, so efficiency naturally takes a hit.
The bracketed DC wattage readings are the ones we observed in NZXT's software.
NZXT CAM Software Screenshots
We took a number of screenshots from the CAM software and compiled them into an album.
The DC power readings are not accurate. Neither is the voltage information.
MORE: Best Power Supplies
MORE: How We Test Power Supplies
MORE: All Power Supply Content
