Skip to main content

NZXT C Series 750W Power Supply Review

Good performance, but the fan profile could be more relaxed.

NZXT C750
(Image: © NZXT)

Protection Features

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

Protection Features

 

OCP

12V: 87.2A (140.65%), 11.909V
5V: 26.1A (130.5%), 4.996V
3.3V: 26.8A (134%), 3.307V
5VSB: 6.2A (206.67%), 4.977V

OPP

1051.81W (141.37%)

OTP

✓ (142.5°C ambient)

SCP

12V: ✓
5V: ✓
3.3V: ✓
5VSB: ✓
-12V: ✓

PWR_OK

Proper Operation

NLO

SIP

Surge: MOV
Inrush: NTC Thermistor & Bypass Relay

The 12V rail has its over current protection triggering point set high, but this doesn't seem to bring any problems. The same goes for OPP. Seasonic wanted to avoid compatibility issues with some GPUs that have high power spikes, so it allowed for higher OCP at 12V. The minor rails have lower OCP triggering points. Lastly, there is over-temperature protection, which is among the most critical protection features, especially in power supplies. 

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.

Image 1 of 3

(Image credit: Tom's Hardware)

DC Power Sequencing Scope Shots

Image 2 of 3

(Image credit: Tom's Hardware)
Image 3 of 3

(Image credit: Tom's Hardware)

The 3.3V rail is always lower than the other two, as the ATX spec requires. 

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

Image 1 of 3

(Image credit: Tom's Hardware)

Load Regulation Charts

Image 2 of 3

(Image credit: Tom's Hardware)
Image 3 of 3

(Image credit: Tom's Hardware)

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.

Image 1 of 4

(Image credit: Tom's Hardware)

Ripple Suppression Charts

Image 2 of 4

(Image credit: Tom's Hardware)
Image 3 of 4

(Image credit: Tom's Hardware)
Image 4 of 4

(Image credit: Tom's Hardware)

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).

Image 1 of 6

(Image credit: Tom's Hardware)

IR Images

Image 2 of 6

(Image credit: Tom's Hardware)
Image 3 of 6

(Image credit: Tom's Hardware)
Image 4 of 6

(Image credit: Tom's Hardware)
Image 5 of 6

(Image credit: Tom's Hardware)
Image 6 of 6

(Image credit: Tom's Hardware)

The hottest part is the main transformer. The secondary side operates at pretty low temperatures, as you can see in the IR images above. 

MORE: Best Power Supplies

MORE: How We Test Power Supplies

MORE: All Power Supply Content

  • Avro Arrow
    Nice-looking PSU. The only problem is that these days, people don't know which way to turn with all of these re-branded PSUs. As you stated, this is the same as the SeaSonic, which makes it good, but there are so many good PSUs that the market is just saturated. Names like EVGA, Antec, Corsair, and Be Quiet! are all top-tier and well-respected names.

    Then in the second tier you get names like Cooler Master, Thermaltake, Gigabyte and ASUS. This NZXT could easily get lost in the mix.
    Reply
  • E-Bert
    a bit late but a question about the noise level, it says 33 decibels average across usage, but if im only using say 550W max load is it ever going to hit that 33 decibels? its the only thing stopping me from picking one up at the moment
    Reply