
The NZXT C850 Gold ATX 3.1 is an 850W fully modular ATX 3.1 power supply with an additional hybrid fan mode.
Priced at $149.99 USD MSRP, this power supply is available in both white and black color options directly from the NZXT webstore. As the newest ATX version, the inclusion of a 12V-2x6 cable ensures it can handle high-wattage GPUs, providing up to 600W.
Performance tests show that this power supply performs well overall, although it lacks a -12V rail, which is not a significant concern. Its resilience to brownouts, low ripple/noise, and high-quality cables make the NZXT C850 Gold ATX 3.1 a recommended choice for those seeking reliability and efficiency in their builds.
WHAT YOU NEED TO KNOW
THE GOOD
- Cables
The included cables are braided and very flexible. The white colorway cables also have all white connectors which is always a bonus.
- Performance
This power supply performs quite well in all areas, achieving great results in our tests with high efficiency at low loads, and low ripple/noise across all rails.
- Resiliency
The C850 Gold ATX 3.1 is very resilient to brownouts, making it a reliable choice.
THE BAD
- Nothing at the time of writing
THE REST
- Overall
We recommend the NZXT C850 Gold ATX 3.1 power supply because it handles brownouts effectively, low ripple/noise, and comes with well-made cables. These factors make it a solid choice for users seeking reliability and performance.
The NZXT C850 Gold ATX 3.1 is an ATX form factor power supply. In the Box, it includes minimal accessories, providing only the essential mounting screws. However, NZXT adds a touch of quality with a signature purple cable bag. While no physical user documentation is provided in the box, it can be easily accessed online through the NZXT product page.
The power supply features high-quality, braided and sleeved cables, with the white model offering matching white connectors.
This unit is equipped with a 135 mm fluid dynamic bearing fan. On the NZXT specifications webpage it specifies that the Operating Temperature is 0°C to 50°C, though we cannot verify this through testing.
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Front of the box.
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Power input side of the PSU.

Top of the PSU displaying the fan.

Bottom of the PSU displaying the specifications.
+12 V | +5 V | +3.3 V | +5 Vsb | -12 V | |
---|---|---|---|---|---|
CURRENT | 70.83 A | 22 A | 22 A | 3 A | N/A |
WATTAGE | 850 W | 120 W | 15 W | N/A | |
850 W |
Please note that the above ratings are manufacturer advertised specifications.
The C850 Gold ATX 3.1 offers two fan modes: Regular Fan Mode and Zero Fan Mode. The Zero Fan Mode is designed for quiet operation, stopping the fan when the load is under 50%. Users can switch between these modes via a physical switch located on the rear of the power supply.
This unit comes with all the standard protections expected from a power supply of its class and is backed by a 10-year warranty.
Although the OCP and OPP thresholds are slightly lower than expected, in the 125-130% range, this does not pose any significant issues. The C850 Gold ATX 3.1 successfully handled power excursions that momentarily reached up to 200%, which is designed to represent real-world 'spikes'.
In terms of performance, the C850 Gold ATX 3.1 power supply demonstrates solid capabilities. During testing, the 12V rail showed a voltage drop of 0.127V across the full 850W output, which remains within ATX specifications and is comparable to other power supplies tested.
This power supply meets ATX ripple specifications and performs better than average, with a peak-to-peak ripple of 22 mV on the 12V rail under full load. The 5V and 3.3V rails also performed well, exhibiting signal ripples of 15 mV and 16 mV. The C850 Gold ATX 3.1 handled power excursions effectively, maintaining voltages within ATX specifications, and should remain stable even under the demands of high-power GPUs.
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The C850 Gold ATX 3.1 is rated at 80PLUS Gold, achieving a 91% efficiency at 50% of its maximum rated load. It also stands out in 2% load efficiency tests, reaching nearly 75%, which is uncommon for power supplies at this level, and those we've tested. Although the 230V 20% efficiency was ever so slightly lower than the required 90% at 89.9%, this could be attributed to minor differences in test setups. However, the power supply's high efficiency below 20% compensates for this.
This power supply is highly resilient to brownouts and power dropouts, enduring a 24 ms dropout at full load for both 115V and 230V inputs. During testing at 20°C and full load, the unit only started failing after 26 ms dropouts, which is the longest duration tested. At 80% load across various temperatures, the power supply passed all test points.
The OPP engaged at a maximum of 125% of the rated load, with the 12V rail alone capable of 88 A, or 125% of its rating. While the trigger points for the OPP and OCP were slightly low, with OPP consistently triggering around 125% and OCP at 120-130%, the power supply still performed reliably, with the exception of the 5Vsb rail, which went up to approximately 160%.
