NZXT C Series 850W Power Supply Review

The NZXT C series power supply with 850W capacity has high build quality and performs well in almost all sections.

NZXT C Series 850W
(Image: © Tom's Hardware)

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Protection Features

Check out our PSUs 101 article to learn more about PSU protection features.

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Protection Features



12V: 97.8A (139.71%), 11.950V, 96.44mV ripple 5V: 27.6A (138%), 5.026V 3.3V: 27.3A (136.5%), 3.312V 5VSB: 6.2A (206.67%), 4.968V


1176.91W (140.11%)


✓ (171°C @ 12V heat sink)


12V: ✓ 5V: ✓ 3.3V: ✓ 5VSB: ✓ -12V: ✓


Proper Operation



Surge: MOV Inrush: NTC Thermistor & Bypass Relay

There is no point in allowing the minor rails going so high, since they are only lightly used by today's PCs. Moreover, the +12V rail goes much higher than 130%, but it manages to keep ripple within the ATX spec's requirements. Nonetheless, close to 100mV ripple is quite high so you should not overload the power supply. Finally, the over temperature protection is set high, since this PSU features a semi-passive operation.

DC Power Sequencing

According to Intel’s most recent Power Supply Design Guide (revision 1.4), the +12V and 5V outputs must be equal to or greater than the 3.3V rail at all times. Unfortunately, Intel doesn't mention why it is so important to always keep the 3.3V rail's voltage lower than the levels of the other two outputs.

There are no issues here, since the 3.3V rail is always lower than the other two. 

Cross Load Tests

To generate the following charts, we set our loaders to auto mode through custom-made software before trying more than 25,000 possible load combinations with the +12V, 5V, and 3.3V rails. The deviations in each of the charts below are calculated by taking the nominal values of the rails (12V, 5V, and 3.3V) as point zero. The ambient temperature during testing was between 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit).

Load Regulation Charts

Efficiency Chart

(Image credit: Tom's Hardware)

Ripple Charts

The lower the power supply's ripple, the more stable the system will be and less stress will also be applied to its components.

Infrared Images

We apply a half-load for 10 minutes with the PSU's top cover and cooling fan removed before taking photos with a modified FLIR E4 camera able to deliver an IR resolution of 320x240 (76,800 pixels).

The hottest part is the main transformer. The temperatures on the secondary side, including the DC-DC converters of the minor rails, stay at relatively low levels.

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Contributing Editor

Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.