Page 2 - Physical Look - Hardware; Installation
As expected from the name, the Noctua NH-U12S chromax.black 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 NH-U12S, the real difference here is the color. There is something that is very fresh about their chromax.black lineup. Its full matte black finish on both the heatsink and the fans is a spectacle to behold. While there are other manufacturers that have employed this color on their CPU coolers, I am still happy to see Noctua do this. This 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 up of aluminum and nickel plating around the entire unit. Noctua's owl logo can also be found engraved on top, which is a nice touch.
From the top, Noctua has implemented a hybrid approach in the leading edges of the heatsink fans. There is a slight V-shaped slope towards the middle on both sides. 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 while reducing the resistance and noise, all while only negligibly decreasing the heatsink surface area. There is a total of fifty 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 unsurprisingly the same as the vanilla NH-U12S.
At a total mass of 580g without a fan and 755g with the single included fan installed, the Noctua NH-U12S chromax.black is notably lighter than the similarly tall NH-U12A. 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 heavy in general, with the largest NH-D15 chromax.black tipping the scales at over 1.3kg with two fans installed. Most of the weight can be attributed to the material choices of the heatsink itself, as you will also find out later.
The single fan on the NH-U12S chromax.black 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 itself to secure the clips. The wire clip retention length is also reduced to a balanced level, so attachment stability is not compromised. Thus, the fans are 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 fans themselves should not need to be removed, except for during installation as the single fan blocks one of the mounting screws.
As for the fans in question, we have a single Noctua NF-F12 PWM chromax.black. We have already reviewed the vanilla NF-F12 PWM fan in the past and it is more than capable. Internally, we have the Noctua SSO2 bearings, which are a hydrodynamic bearing for quieter operation and longer life. The 120mm fan has a specified rotational speed range of 300 to 1500 RPM, maximum airflow rating of 93.4 cubic meters/hour, and static pressure of 2.61 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 fans in this size. In addition, with this full black version, I doubt anyone would care to now.
Taking a step back, the Noctua NH-U12S chromax.black dimensions are what you might expect. It measures 158 mm in height, 125 mm in width, and 45 mm in depth. With the single included fan installed, the depth increases to 71 mm. At 158 mm in height, this is probably out of the question for use in slimmer media computer cases, but should be fine for most mid-tower ATX cases. The NH-U12S chromax.black is symmetrical, as it is slim enough to avoid overhanging into the memory area. 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 10 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-F12 PWM chromax.black 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, so 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 4cm from the bottom of the base to the lowest fin, Noctua mentions this cooler has full compatibility with the modern Intel LGA115x 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-U12S chromax.black 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, though 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 chromax.black finish everywhere except for the base, which is understandable. 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-U12S chromax.black 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-U12S chromax.black conceals the copper color with its copper heatpipes and base. 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-U12S chromax.black 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-U12S chromax.black appears to be built very solidly. 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 between the two for parts. 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 NH-U12S chromax.black onto an 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. While most users will not see these mounting bars after installation, I appreciate this attention to detail.
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-U12S chromax.black, 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-F12 PWM chromax.black fan to the heatsink. As I have noted before, the NH-U12S chromax.black does not interfere with my RAM, as the cooler has quite a small horizontal 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.
1. Introduction, Packaging, Specifications
2. Physical Look - Hardware; Installation
3. Test Results