Noctua NH-U9S Review (Page 2 of 4)

Page 2 - Physical Look - Hardware; Installation

As expected from the name, the Noctua NH-U9S is an all-black version of the original NH-U9S. It is designed like other U-series Noctua coolers with a single stack of fins and several heatpipes going through it. As we have already reviewed the vanilla NH-U9S, the real difference here is the color. Its full matte black finish on both the heatsink and the fan is truly beautiful. While there are other manufacturers that have employed this color on their CPU coolers, I am quite happy to see Noctua do this. There is a black coating over all of the heatsink, but it was important that this coat does not increase thermal resistance and impact its ability to move heat away. The heatsink is still made out of aluminum around the entire unit with a nickel plated copper base. Noctua's owl logo can also be found engraved on top, which is a nice touch.

As you see from the top, Noctua has implemented a hybrid approach in the leading edges of the heatsink fins. There is a slight V-shaped slope towards the middle on one side. The other edge has a larger semi-circular cutout so users can reach the installation screw, but you will see more on this later. There are also a few zigzagged teeth on both sides of the metal fin edges. Both of these optimize the ability to permit airflow in between the fins and reducing the resistance and noise at the same time, all while only negligibly decreasing the heatsink surface area. There is a total of forty-three fins on the radiator. The spacing in between each fin is approximately 2.0mm. From my calculation, the total surface area of the cooling fins combined is close to 0.54 square meters, which is reasonable when you consider the size. At a total mass of 618g with the single included fan installed, the Noctua NH-U9S is the same weight as the original NH-U9S. For some perspective, a typical Intel stock cooler is a lightweight at 330g, while an AMD Wraith Prism stock cooler weighs 582g. Noctua heatsinks are heavier than stock options in general. Most of the weight can be attributed to the size and material choices of the heatsink itself, as you will also find out later.

The single fan on the NH-U9S is held on with two wire clips that are easy to remove. This is the same fin system employed by Noctua for quite a while, as they keep the fan sturdily mounted to the heatsink. It clips on the outside of the fan and goes around the side of the heatsink fins. Raised edges are integrated into the fin structure to secure the clips. The wire clip retention length is also reduced to a balanced level, so attachment stability is not compromised. Thus, the fan is easier to remove with these tabs and the clips can be removed uniformly. The wire clips also have an advantage by allowing users to be a bit more flexible in terms of the fan-heatsink location. The included Noctua NF-A9 PWM will need to be removed during installation, as it blocks one of the mounting screws.

As for the fan in question, we have a single Noctua NF-A9 PWM Internally, this fan uses Noctua SSO2 bearings, which are a hydrodynamic bearing for quieter operation and longer life. The 92mm fan has a rotational speed range of 400 to 2000 RPM, maximum airflow rating of 78.9 cubic meters/hour, and static pressure of 2.28 mmH2O. It also comes with a low noise adapter, which reduces all of the numbers I have stated above in order to keep the output noise low. Rated mean time before failure is approximately 150,000 hours, which is just over seventeen years. While you could find different fans to place on the heatsink, I would not recommend swapping them out, as these are one of the best performing fans in this size.

Taking a step back, the Noctua NH-U9S dimensions are relatively compact, but this is also what you might expect for a 92mm sized cooler. It measures 125 mm in height, 95 mm in width, and 68 mm in depth. With the single included fan installed, the depth increases to 95 mm. At this 125mm height, this should fit in slimmer cases, but it obviously varies based on the enclosure you use. The NH-U9S is asymmetrical to avoid overhanging into the memory area even with the fan installed. From the base where the metal makes contact with the processor, five continuous U-shaped heatpipes lead away from the CPU contact, splitting into two sides of the same radiator to dissipate the heat. This effectively makes ten heatpipes in total. The heatpipes are supposed to efficiently lead the heat away from its source due to the low heat of vaporization, or phase change energy, of alcohol. The heatpipes are aligned in an alternating manner to spread out the heat in the single array of radiating fins. The 0.54 square meters of surface area, combined with a NF-A9 PWM fan, should be able to deliver very good heat dissipation performance, but we will see if this statement is true on the next page.

This CPU cooler is aligned such that when the single fan is attached in its default position, there is no part hanging over into other areas on the motherboard like the motherboard or the first PCI Express slot underneath. With a clearance of approximately 3.2cm from the bottom of the base to the lowest fin, Noctua mentions this cooler has full compatibility with the modern Intel LGA115x and LGA1200 sockets and AMD AM4 without any interference with memory. The downside to this is you are not going to get much, if any, airflow in the area between the contact base and the first cooling fin generated by the intake fan, since it does not extend into this area.

The photo above shows a shot of the bottom of the Noctua NH-U9S CPU heatsink and the configuration of the heatpipes more clearly in relation to the base leading into the fin array. You can see the base is very flat, which means practically the entire base should rest evenly on top of the processor. A quick inspection also reveals there are no abnormalities here, although on closer inspection, some of the circular milling marks are visible when they finished the surface. As well, you can tell they have put the finish everywhere except for the base, which is expected. As we have seen from past Noctua heatsinks, this heatsink is composed of copper, nickel, and aluminum. The base and heatpipes are built using copper for best heat transfer ability with a thermal conductivity of 401 W/mK. The heatsink fins utilize aluminum as it is quite a bit lighter in comparison to copper. This compromise allows the NH-U9S to reduce its weight and thus reducing the stress on the motherboard. Aluminum has a thermal conductivity of 237 W/mK, which is not as optimal for heat transfer, but the trade-off is understandable.

Visually speaking, the Noctua NH-U9S conceals the copper color with a black coat over the nickel-plated cover. The electroplating of the base with nickel on top of copper has a thermal conductivity of only 90.9 W/mK. While nickel has a lower thermal conductivity than copper, the electroplated layer is very thin and should not directly affect performance to a significant degree. Instead, this is done this way to keep the base from corrosion. Nickel and nickel-base alloys generally have desirable properties that can withstand corrosive environments and high temperatures, which are especially beneficial for a heat dissipation device. The reason why nickel has such a property is because of nickel's ductility and toughness all the way up to the melting point of 1455c, measured at non-standard pressure. Nickel's face-centered cube crystal structure is virtually unaltered all the way up to that temperature. Nickel, like titanium, is highly resistant to corrosion so corroded material will not build up on the surface in the long run. As a result, the Noctua NH-U9S will be less prone to losing its cooling performance over time as juxtaposed to a corroded copper surface.

Additionally, all the joints are cleanly soldered at the base while the heatpipes are soldered to the fins. Pressed fins are typical for most heatsinks, but this can lead to degradation over time as contact between metals decreases due to thermal expansion and contraption. Overall, the Noctua NH-U9S appears to be built very solidly, though some of the fins are slightly bent closer to one another. It is nothing out of the ordinary and these uneven gaps can be bent back to their correct position. Reliability should also be excellent and Noctua offers a six-year warranty should anything go wrong.

As you have read in our other Noctua reviews, installation is straightforward and easy. The same system used with practically all of Noctua's heatsinks is found here, which they call the SecuFirm2 system. Therefore, if you have another recent Noctua cooler, you can exchange parts between the two. If you are installing into an Intel system, you can use the included metal backplate with part number NM-IBP2. This comes with fixed bolts for easier installation of the entire unit. However, if you are installing the Noctua heatsink onto a recent AM4 AMD motherboard, you can use the integrated plate that you will have received with your motherboard.

On the other side, two mounting bars are included to attach the heatsink to the motherboard. Once the backplate is mounted, the plastic spacers can be installed to space out the mounting bars. With an Intel system, the two mounting bars can be placed in a horizontal or vertical configuration, depending on what the user chooses for their installation orientation. The bars included here are the NM-IMB3, which are the same mounting bars found with other U-series heatsinks. With an AMD system, like the one I have above, the bars included here are the NM-AMB11. These are screwed into the backplate with the plastic spacers in between, and only fit in one orientation. Once you tighten the thumb bolts on the bars, you can install the heatsink. One thing I really appreciate is the fact all of these accessories are also black, while the vanilla versions of these heatsinks are silver.

Before doing so, be sure to place a bit of thermal paste between the processor and the heatsink. On an AMD processor, like the recent Ryzen CPUs, Noctua advises to put a small dot measuring in 4 to 5mm in diameter, with a square pattern of four dots surrounding the middle one. Next, remove the attached fan from the NH-U9S and place the heatsink over the two protruding screws on the mounting bars. At this point, I would recommend you to use the screwdriver provided, as accessibility to the screw can be limited. With this tool, tighten the screws, alternating between each screw to evenly attach the heatsink to the motherboard. Finally, reattach the NF-A9 PWM fan to the heatsink. As I have noted before, the NH-U9S does not interfere with my RAM, as the cooler has quite a small footprint. With the physical inspection, we can see Noctua is consistent in both its build quality and aesthetics as it has been with past products, and the installation process is among the best.

Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Hardware; Installation
3. Test Results
4. Conclusion