NZXT C1200 Gold ATX 3.1 1200w Fully Modular Power Supply Review

NZXT is a well-renowned name in the PC gaming industry. It has consistently delivered high-quality components with a focus on both performance and aesthetics with its PC cases, coolers, peripherals, audio gear, motherboards and more. Their latest offering, the C1200 Gold ATX 3.1 PSU, continues this tradition, aiming to provide reliable and efficient power for even the most demanding systems on the market today, as well as the next generation of hardware, such as the NVIDIA GeForce RTX 40 series and upcoming 50 series of graphics cards. NZXT C1200 Gold ATX 3.1 One of the standout features of the C1200 Gold is its adherence to the ATX 3.1 standard. This ensures compatibility with the latest components and provides a stable platform for future upgrades. A key element of this standard is the 12VHPWR connector, specifically designed to handle the power demands of high-end GPUs, delivering up to 600 watts directly to the graphics card. Of course, with a 1200W output, the C1200 can do much more than that, dealing with enthusiast hardware such as flagship CPUs more easily. Being the "Gold" edition, it also boasts an 80 PLUS Gold certification, meaning less power is wasted, lower electricity bills, and a reduced environmental impact. Sure, you could go further and get a Platinum or Titanium PSU, but for a 1200W unit to be that efficient, you can be paying upwards of £400, while the C1200 is just £159.99. Features Compliant with the ATX 3.1 standard to fuel high-performance PC components with stability, efficiency, and power spike resistance. Durable, heat-resistant 12V-2x6 connector pumps up to 600 watts to NVIDIA® GeForce RTX™ 40 Series graphics cards. 135mm fluid dynamic bearing fan with Zero Fan Mode is completely silent when under 50% load. 100% premium Japanese capacitors improve hold-up time and minimal ripple noise, ensuring reliable and stable power delivery. Fully modular design allows for only connecting essential cables, reducing clutter for better airflow and a neater build. Compact form factor frees up valuable room for cable management and more case airflow. Thanks to high-quality construction and rigorous product testing, NZXT PSUs are backed by a 10-year warranty. Silence NZXT has also prioritised quiet operation with the C1200 Gold. Achieving a Cybenetics A- noise level rating, meaning it should operate quietly even under heavy load thanks to its 135mm fluid dynamic bearing (FDB) fan, which also supports a Zero Fan Mode below 50% load for total silence. Japanese Capacitors The C1200 Gold utilises 100% Japanese capacitors, known for their reliability and longevity. These components contribute to improved hold-up time (the ability to maintain power output during brief power interruptions) and reduced ripple noise, ensuring clean and stable power delivery to sensitive components. Of course, we'll be putting that to the test shortly. Fully Modular The C1200 Gold's fully modular design adds to its appeal. This allows users to connect only the cables they need, minimising cable clutter within the case and improving airflow. This, coupled with its compact form factor, makes the C1200 Gold a suitable choice for a variety of PC builds, even those with limited space. Furthermore, NZXT backs the C1200 Gold with a 10-year warranty, providing peace of mind and demonstrating their confidence in the product's long-term reliability. For further specifications, please check out the official product page here. A Closer Look NZXT has a range of great-looking products, and they always look great together, because they use the same design principles with them all. Matte finish paints with a light texture, the same ventilation patterns, the same fonts, and subtle details such as rounding off some of the corners and edges. As you can see, all of these design aspects can be found on the NZXT C1200. This isn't the most outlandish-looking PSU ever, but it doesn't need to be. However, it is certainly very attractive, and it looks and feels like a quality product, which is what I would want to feel about an expensive 1200W power supply. At 1200W it will likely power a pretty expensive computer, so it gives you a bit of confidence. There's a master power switch on the rear of the power supply, as well as a zero RPM fan mode switch, which can allow the fan to stop in low load and/or low temperature operation. All the connectors are neatly laid out, with everything separated and labelled for ease of use. There are six CPU/PCI-E connectors, one of which is the newer 12V 2x6 connector. There are four peripheral connectors, and of course, the 24 pin connector (split into a 20+4 configuration). A Closer Look - Interior The cooling fan is a Hong Hua, which is pretty common on modern PSUs and is a brand that is well known to be excellent quality and very reliable. The PSU you're using right now likely has a Hong Hua fan, as seemingly every brand uses them these days. NZXT looks to be built around one of the most recent CTT designs, using a semi-digital platform for the 1200W version, and premium-quality components throughout. Of course, that's not surprising given NZXT is a quality brand and you tend not to get to 1200W easily with cheaper components. It features a of Rubycon main bulk capacitor, operating at 420v and 1150uF, rated to operate at up to 105c, and that should easily help make up the 1200W main voltage, if not a fair bit more actually, as it's one of the largest single bulk capacitors I've seen in a PSU. The design is a half-bridge topology, with an LLC resonant converter, again part of the semi-digital design which will help with reducing any heat generation and with improving efficiency. There are the usual DC-to-DC converters for the 3.3v and 5v rails, but overall, it's a pretty straightforward design here, with all the components neatly laid out, good airflow throughout, and clean soldering on all the major components. There are a few small heatsinks, but they appear to be of good quality, and again, there's plenty of ventilation here so I doubt heat will ever be an issue; clearly NZXT feel the same, hence the zero RPM fan mode. Methodology & Testing At eTeknix we take the power supply testing procedure very seriously and have invested a lot of resources into acquiring the appropriate testing equipment. For all power supply reviews, we test the power supplies with dedicated power supply testing equipment. This means we can get the most accurate results from our testing as opposed to using software benchmarks (such as OCCT) or multi-meter readouts which are broadly inaccurate. Testing Hardware Sunmoon SM-8800 Active Load Tester Stingray DS1M12 USB Oscilloscope Voltcraft DT-10L laser tachometer What the eTeknix Test Procedure Involves Testing each power supply at 20/40/60/80/100% load (with load balanced across all rails) and measuring PFC (power factor correction), efficiency (actual power divided by power "pulled at the wall") which also uses a 50% load test, and voltage regulation (deviance from expected voltages of 3.3/5/12 on the main rails). Measuring ripple with an oscilloscope at 20/40/60/80/100% load. Transient loads taken with an oscilloscope are taken from 0% to 100% on the 12v raid, 3.3v rail, and then both combined. Measuring fan speed after a stabilisation period of five minutes at each loading scenario using the Voltcraft DT-10L laser tachometer and a reflective strip on the fan. Testing each power supply's OPP (Over Power Protection) mechanism and seeing how many watts each power supply can deliver before shutting down. Any deviation from this will be explained per review as appropriate on the respective testing pages, but this methodology page will remain unchanged. Other Things to Consider We recognise that a single 12-volt cable can provide only 6 Amps before overheating (which corrupts voltage regulation and efficiency) so we used an adequate number of cables for each power supply to ensure there is no efficiency loss from poor cable selection. If there is more than one 12VHPWR on a PSU, all will be used to test their combined loads. We use the same time scale and horizontal millivolt scale on our oscilloscope for all ripple tests, that is a 20ms T/DIV (horizontal) and a 0.02 V/DIV (vertical) meaning the scale is from -80mV to +80mV, ATX spec dictates that the 12v rail must fall within 150mv of ripple and the 3.3/5 within 50mv so that scale allows us to include both 150 and 50mV peaks. (Some older PSU reviews use different scales which were later ditched as the visual representation they give is inadequate, in these reviews written measurements are provided only). Deviance is the terminology used to represent the way voltages diverge from the expected values Voltage Regulation To test voltage regulation we load the power supply to five different load scenarios that give an equal spread of load across every single rail. So that means 20% on all rails, 40% on all rails and so on. We then calculate the average deviation of each rail from its expected voltage. Ideally, anything of +/- 2% regulation is seen as a very good result. Power Efficiency Power efficiency is measured by calculating the supplied wattage divided by the wattage drawn at the wall/plug, multiplied by 100 to give a percentage. We then compare that to the particular 80 Plus certification the company claims to see if it meets that. You can see the 80 Plus certifications below, we always test power supplies at 230v. Transient Loads Power Factor Correction Power Factor Correction is the ratio of the real power flowing to the load, to the apparent power in the circuit. PFC aims to make the load circuitry that is power factor corrected appear purely resistive (apparent power equal to real power). In this case, the voltage and current are in phase and the reactive power consumption is zero. The closer the number to one the better as this allows the most efficient delivery of electrical power (Source - Wikipedia). Ripple An oscilloscope can easily measure noise and Ripple. These show how much voltage fluctuation there is on a particular rail. We tested the rail stability of the 3.3-volt, 5-volt and 12-volt rails using an identical time and millivolt scale for all graphs. millivolt ripple is measured by the peak-to-peak size of the voltage curve. The latest ATX 12-volt version 2.3 specifications state that ripple from peak to peak must be no higher than 50 millivolts for the 3.3-volt and 5-volt rails, while the 12-volt rail is allowed up to 120 millivolts peak to peak to stay within specifications. Millivolt figures are stated to the closest increment of 5 given their variability. OPP Power supplies are often quoted as having various protection mechanisms and the most important of these is Over Power Protection. In our testing, we crank up the power draw until the power supply either shuts down (meaning the OPP mechanism is present and working) or blows up (meaning it is either not present or not working). We then note the maximum power consumption before the power supply shut down, or before it blew up. Fan Speed When testing in a power supply laboratory it is difficult to take fan noise readings as the noise from the Sunmoon test equipment and air conditioning corrupts everything. The next best thing in our circumstances was reading off the fan speed with a tachometer to get an idea of the noise. The ambient temperature during testing is held constant at 22 degrees, with 1 degree of variation. Each power supply had a consistent period of 5 minutes to stabilise between each load scenario. In my experience, the following general relationships apply between noise levels and fan speeds, though it can vary greatly between the type of fan used. Below 800 RPM - Inaudible/Silent 800 to 1000 RPM - Barely audible 1000 - 1200 RPM - Audible but still quiet 1200 - 1400 RPM - Moderately noisy 1400 - 1800 RPM - Noisy 1800 - 2000 RPM or above - Intolerable Internal Components This is just an example of what you can expect to see on a PSU interior. Efficiency The efficiency is very good, with the NZXT C1200 coming in as an 80 Plus Gold-rated unit, it's very efficiency. Sure, you could move up to Platinum or even Titanium-rated units, but at 1200W, you can expect the price to go up quite dramatically for such a unit. PFC (Power Factor Correction) Again, pretty predictable here, with very good PFC throughout my testing, especially so from 40% load and upwards, meaning very little power is wasted and less heat will be generated as a result. Voltage Regulation Voltage regulation is as good as you could ever hope for, and we typically want to see within 3%, but as you can see, it's all within 1% throughout every load, so really no issues here at all. Ripple Ripple is fantastic too, but again, I wasn't expecting anything less. Typically we want to see under 50mv on the 12v and 150mv on the rest, and the figures here are clearly drastically under that by a significant margin. That being said, I haven't seen a PSU with bad ripple on my test bench in many years, the market has come a long way that the old standards seem pretty silly compared to the results we see. 3.3V 5V 12V Over Power Protection and Max Wattage 1200W is a lot of power, but as I said before, those two massive bulk capacitors are pretty serious so my suspicions that it would exceed 1200W are easily confirmed, clocking in at 1515W before the OPP kicked in a shut things down. Fan Speed The fan is nice and quiet on the PSU, even at full load it wasn't particularly aggressive and didn't need to be thanks to the great efficiency and PFC, it's designed to not get too warm to begin with. However, with the zero RPM fan mode enabled, the fan doesn't spin at all at lower loads, making it completely silent. How Much Does it Cost? NZXT C1200 Gold ATX 3.1 1200w Fully Modular Power Supply is available now from Amazon for just £184.99, which is a lot of money, but keep in mind this is a Gold Rated 1200W power supply, it's a high-end unit, but for the power you get, and the performance, I think the price is very reasonable. Even better if you're buying it right now, as at the time of writing it was on sale for just £144. Overview The NZXT C1200 Gold ATX 3.1 PSU is an excellent choice for high-end PC builds. It offers a competitive combination of performance, efficiency, and features, all at a very competitive price point. Ready for current and next-generation hardware, it adheres to the latest ATX 3.1 standard, including the crucial 12VHPWR connector needed to power the most demanding graphics cards, like the NVIDIA GeForce RTX 40 series, and most likely the 50 series, and upcoming AMD hardware too. Efficiency Efficiency is a key strength, with the C1200 Gold boasting an 80 PLUS Gold certification that reduces wasted power and helps lower your electricity bills. Sure, we'd all like Platinum or Titanium rated units, but their prices are often double and likely not worth the investment for most PC gaming builds. NZXT has also prioritised quiet operation, achieving a Cybenetics A- noise rating. This is thanks in part to the 135mm fluid dynamic bearing fan which supports a Zero Fan Mode, allowing for silent operation under low loads, and still pretty quiet even at maximum loads. The high-quality components, such as the 100% Japanese capacitors used in its construction, ensure long-term reliability and even allowed it to exceed the 1200W rating pretty easily. Modular The fully modular design is a welcome addition, allowing users to connect only the necessary cables, which minimises clutter and improves aesthetics within the case. Its compact form factor makes it suitable for a variety of PC cases, even those with limited space, it's easy to accomodate this 1200W unit. Performance In terms of performance, the C1200 Gold excels. Voltage regulation is superb, consistently staying within 1% of expected values across all load levels. Ripple suppression is also fantastic, ensuring clean and stable power delivery. The unit effortlessly handles its 1200W rating and even pushes beyond that, reaching 1515W before the over-power protection activates. The fan remains quiet even under load, and with Zero Fan Mode enabled, it's silent during daily usage. Should I Buy One? Priced competitively at £184.99 (with potential for discounts depending on current sales), the NZXT C1200 Gold offers great value. It's a high-end unit with a strong set of features and impressive performance, making it a worthwhile investment for any enthusiast PC builder looking for a top-tier power supply. Furthermore, NZXT provides a 10-year warranty on the C1200 Gold, demonstrating their confidence in its durability and giving users peace of mind.