While a stock cooler is supplied with most retail CPUs, enthusiasts often want something better; be it a more powerful cooler, a quieter cooler, a liquid cooler, etc. As a result the market for third-party coolers remains strong, providing variety against the backdrop of more limited stock coolers. And with that, there's no shortage of designs, with coolers for pretty much ever need, want, budget, and size limitation.

In today's review we are taking a look at the NH-U12A, a tower CPU air cooler made by Noctua. Noctua is a company renowned for its advanced products that usually – and deservedly – carry a premium price tag. The NH-U12A is the latest version of their family of 120 mm-based single-tower CPU coolers, which are designed to offer a balance between performance, cost, complexity, and compatibility.

Overall, the NH-U12A is designed to fit top-tier cooling performance into a more compact 120 mm cooler, as opposed to larger and more traditional 140 mm coolers. In this respect, it's especially useful for users building compact and transportable gaming systems.

Diving right in, we received the NH-U12A in an exceptionally sturdy cardboard box. Noctua is using the same simple artwork on the packaging of all their products, focusing on elegance and the provision of information rather than an eye-catching design.

Inside the box, we found the cooler very well protected, placed below layers upon layers of thick cardboard packaging. The supplied mounting hardware and extra items can be found in a smaller, compartmentalized cardboard box.

Aside from the typical mounting hardware necessary to mount the NH-U12A onto a CPU socket, Noctua also supplies a basic screwdriver, a fan power splitter cable, two fan “low noise” adapters that limit the speed of the cooling fans, a tube of NT-H1 thermal grease, and a metallic case badge.

The Noctua NH-U12A CPU Cooler

Noctua designed the NH-U12A to be a high performance CPU cooler, yet not too large or too expensive. The use of 120 mm fans allows the NH-U12A to be compatible with more cases and a bit easier to install as well, while it also reduces the manufacturing cost of the cooler a little. Overall, the NH-U12A is compatible with most of the motherboards and processors released in the past several years, including LGA 2011 and LGA 2066 processors. The only processor socket of note that it's not compatible with is AMD's socket TR4 for Threadripper processors; these large processors require a matching larger base, and Noctua has the NH-U12S TR4-SP3 specifically for that processor.

Physically, the NH-U12A is relatively simple. It is a single tower cooler, with the array of fins floating above a small base and relying on heatpipes to transfer the thermal energy away from that base and to the main body of the cooler. Despite the 120 mm fan size, the NH-U12A is not exactly compact – it is short enough to fit inside the majority of ATX-compliant cases, but the fin array is thick and the presence of two 120 mm fans makes the cooler even wider. Even though Noctua made sure that the NH-U12A will stay clear of the PCI Express slots, the cooler will cover a significant portion of the motherboard and is very likely to hang over the RAM slots on many boards, limiting RAM height on these slots to 42 mm.

Noctua claims that the NH-U12A brings 140 mm cooler performance in 120 mm size. We can see why, as the array of fins is significantly wider than that of the NH-U12S, a cooler that the company introduced as a top-tier 120 mm cooler and even made a Threadripper-specific version of it. Aside from the wider array of fins, the cooler has seven heatpipes, accelerating heat transfer even further. The heatpipes are made of copper but are nickel-plated. The joints are all soldered, ensuring maximum thermal transfer and mechanical cohesion.

Due to the dense fin array, Noctua’s engineers had to optimize air pressure and went with two fans instead of one. The fans used are the company’s own 120mm NF-A12x25 fans, which combine airflow with good air pressure, making them ideal for fan speed controlled CPU coolers. Still, it appears that the very dense array of fins on the NH-U12A forced the designers to use two fans in order to maintain viable airflow levels, at least when the speed of the fans is low.

The base of the cooler that makes contact with the processor is split into two parts. The bottom half of the base is made out of nickel-plated copper, maximizing the heat transfer rate from the CPU to the heatpipes. It is extremely well machined, perfectly flat and smooth. The top half serves only as a mechanical support and is made out of aluminum, while the mounting bracket is nickel-plated steel.

Testing Methodology

Although the testing of a cooler appears to be a simple task, that could not be much further from the truth. Proper thermal testing cannot be performed with a cooler mounted on a single chip, for multiple reasons. Some of these reasons include the instability of the thermal load and the inability to fully control and or monitor it, as well as the inaccuracy of the chip-integrated sensors. It is also impossible to compare results taken on different chips, let alone entirely different systems, which is a great problem when testing computer coolers, as the hardware changes every several months. Finally, testing a cooler on a typical system prevents the tester from assessing the most vital characteristic of a cooler, its absolute thermal resistance.

The absolute thermal resistance defines the absolute performance of a heatsink by indicating the temperature rise per unit of power, in our case in degrees Celsius per Watt (°C/W). In layman's terms, if the thermal resistance of a heatsink is known, the user can assess the highest possible temperature rise of a chip over ambient by simply multiplying the maximum thermal design power (TDP) rating of the chip with it. Extracting the absolute thermal resistance of a cooler however is no simple task, as the load has to be perfectly even, steady and variable, as the thermal resistance also varies depending on the magnitude of the thermal load. Therefore, even if it would be possible to assess the thermal resistance of a cooler while it is mounted on a working chip, it would not suffice, as a large change of the thermal load can yield much different results.

Appropriate thermal testing requires the creation of a proper testing station and the use of laboratory-grade equipment. Therefore, we created a thermal testing platform with a fully controllable thermal energy source that may be used to test any kind of cooler, regardless of its design and or compatibility. The thermal cartridge inside the core of our testing station can have its power adjusted between 60 W and 340 W, in 2 W increments (and it never throttles). Furthermore, monitoring and logging of the testing process via software minimizes the possibility of human errors during testing. A multifunction data acquisition module (DAQ) is responsible for the automatic or the manual control of the testing equipment, the acquisition of the ambient and the in-core temperatures via PT100 sensors, the logging of the test results and the mathematical extraction of performance figures.

Finally, as noise measurements are a bit tricky, their measurement is being performed only manually. Fans can have significant variations in speed from their rated values, thus their actual speed during the thermal testing is being acquired via a laser tachometer. The fans (and pumps, when applicable) are being powered via an adjustable, fanless desktop DC power supply and noise measurements are being taken 1 meter away from the cooler, in a straight line ahead from its fan engine. At this point we should also note that the Decibel scale is logarithmic, which means that roughly every 3 dB(A) the sound pressure doubles. Therefore, the difference of sound pressure between 30 dB(A) and 60 dB(A) is not "twice as much" but nearly a thousand times greater. The table below should help you cross-reference our test results with real-life situations.

The noise floor of our recording equipment is 30.2-30.4 dB(A), which represents a medium-sized room without any active noise sources. All of our acoustic testing takes place during night hours, minimizing the possibility of external disruptions.

*noise levels above this are not suggested for daily use

Testing Results, Maximum Fan Speed (12 Volts)

Starting things off, let's take a look at the NH-U12A performance with the fans at their full speed (12 V).

Noctua claims that the NH-U12A can compete directly against 140 mm coolers. Although it is not really quite as good as advanced 140 mm coolers – at least when compared to the likes of the NH-U14S and the Phanteks PH-TC14PE – the thermal performance of the NH-U12A definitely is excellent for a 120 mm cooler. Which, in turn, is good enough to just touch the performance of simpler or silence-oriented 140 mm cooler designs, such as the Thermalright True Spirit.

The Noctua NH-U12A performs exceptionally well at the lower end of the load spectrum, outperforming even several 140 mm coolers at loads lower than 80 Watts. The gap widens as the load increases but the thermal performance of the NH-U12A always remains respectable. It is noteworthy to mention that the high thermal performance is complemented by respectable acoustics performance; even with the cooler's fans spinning at their maximum speed, the NH-U12A is audible but not too loud.

Testing Results, Low Fan Speed (7 Volts)

Switching things up a bit, let's next take a look at cooler performance with the NH-U12A fans taken down to 7 Volts.

With the speed of its fans reduced down to 800 RPM, the NH-U12A becomes virtually inaudible to a user that sits one meter away from it. The thermal performance still comes close to 140 mm coolers, with the NH-U12A being unable to match it but landing near them, all while outperforming most other similarly-sized cooling solutions.

A closer look at the charts reveals that the NH-U12A actually is rather efficient with the handling of very heavy thermal loads even with reduced airflow. This suggests that the cooler will be able to handle overclocked processors without the thermal control of the motherboard having to shoot the speed of the fans too high, maintaining low noise levels.

Thermal Resistance VS Sound Pressure Level

During our thermal resistance vs. sound pressure level test, we maintain a steady 100W thermal load and assess the overall performance of the coolers by taking multiple temperature and sound pressure level readings within the operating range of the stock cooling fans. The result is a graph that depicts the absolute thermal resistance of the cooler in comparison to the noise generated. For both the sound pressure level and absolute thermal resistance readings, lower figures are better.

Expectedly, the performance chart of the Noctua NH-U12A lands right above that of its larger counterpart, the Noctua NH-U14S. The difference is very small (practically negligible), confirming Noctua’s claims that the NH-U12A can compete head-to-head with performance-oriented 140 mm fan coolers. For example, NH-U12A's performance advantage over a popular and significantly lower-priced tower cooler, the Cooler Master Evo 212, is momentous, partially justifying the retail price difference between the two products.

Conclusion

Noctua designed the NH-U12A to cover a very specific portion of the market – users that want a top-tier air cooler but are limited by the space available in their systems. Although this rarely is a concern for home users with high-end ATX tower cases, it is a growing issue for those building compact gaming systems, be it for living room use or just easier transportation.

To that end, Noctua’s engineers had to develop a cooler that competes with larger variants but fits into compact and HTPC cases. The solution seems simple at first – a modest increase of the NH-U12S’s mass would definitely improve the cooler’s performance. However, chaotically increasing a cooler’s size is a harbinger to compatibility issues. Fortunately, Noctua’s engineers never do anything randomly. The new NH-U12A is designed to specifically stay clear of the PCI Express slots, ensuring that the installation of the cooler will not be blocked by the graphics card. The cooler may partially overhang some of the RAM slots, but regular modules not taller than 42 mm will still fit. Finally, they balanced the length and density of the fins (airflow impedance) with the capabilities of the two 120 mm fans perfectly, ensuring good overall performance.

Noctua claims that the NH-U12A can compete head-to-head with 140 mm tower coolers. Though this definitely isn't true in all situations, when the thermal load is relatively low, the cooler can actually live up to Noctua's claims. With "relative" being, well, relative, by tower cooler standards, as high-end coolers can easily dissipate better than 200 Watts. This means that the NH-U12A will perform just like (or even better than) a 140 mm cooler with many stock-clocked processors, as only a handful of chips actually draw more than a 100 Watts or so.

Otherwise, once we start looking at high TDP scenarios, the larger 140 mm coolers of comparable class and quality will outperform the NH-U12A, even if only slightly. Noctua can't entirely escape the laws of physics here in that regard, as volume and surface area still count for something.

Past that, it's worth noting that the NH-U12A continued to display very good thermal performance even when the speed of the fans is reduced down to inaudible levels, making it an excellent choice for living room usage scenarios.

The only real drawback to the NH-U12A is its retail price, which is above and beyond even the usual Noctua premium. With US listings running at around $100, the cooler is going for roughly double the price of the similar NH-U12S, and the same has been true in Europe as well. As best as I can figure, the use of two high-end NF-A12x25 fans has significantly increased the production costs of the NH-U12A.

As a result the NH-U12A is, at least at the moment, a true niche product. Within its 120 mm space it's the tower cooler to beat. But if you can fit a larger 140 mm cooler, then this opens the door to a number of cheaper and equally capable coolers, including Noctua’s own top-tier 140 mm coolers, which currently sell for less than the NH-U12A. None of which changes the fact that the NH-U12A is a fine cooler, but as things stand the potential market is limited to users who want a high-end cooler for a compact system that can't fit something larger.