Page 2 - Physical Look - Hardware; Installation
The Noctua NH-L12Sx77 has a low-profile cooler design. It is meant to provide excellent cooling in small form factors where height is a limitation. This is one reason why the fan is mounted where it is. The fan does not take up extra room on top of the fins, but it could if you had the room. A striking aspect of it is its mostly horizontal design. The heatsink will sit over the memory sticks when it is installed, which means they cannot be removed to make more room for the installation. The cooler is mostly silver in color, while the fan provides the only color contrast with the rest of the cooler. The fan has the usual Noctua colors, which has its own appeal. Other than the fan, there is no branding on the heatsink itself. The measurements for the NH-L12Sx77 come in at 77mm in height, 128mm in width, and 131mm in depth. If you placed the fan on top of the cooler, it would add 15mm in height. This would only really be necessary if you need extra clearance for tall-profile RAM. The weight for the cooler is 410g without the fan, and 520g with the fan.
The Noctua NH-L12Sx77 has a typical design for a low-profile air cooler. Similar to the original NH-L12, the fins sit perpendicular to the motherboard. The many fins you see are built from aluminum, which provides a balance between cooling capability, cost, and weight. As you can see, there are 55 fins that surround six heatpipes. The total surface area of the fins is approximately 0.34m². The heatpipes connect directly to the CPU block, which is where most of the heat is generated. The fins help to dissipate the heat as air flows over them. The heatpipes are spaced evenly along the fins. A unique feature of the NH-L12Sx77 are the square cutouts in the fins. These are there so that you can fit a screwdriver through the top into the mounting hardware under the fins.
From above, you can see a closer look at the CPU block base. It is pretty flat with just some circular milling marks observed. The mirror-like finish shows off the nickel-plated finish, which is also seen on the heatpipes of the Noctua NH-L12Sx77. While nickel has a notably lower conductivity of 90.9W/mK, this layer is very thin and should not adversely affect the performance to a significant degree. Instead, nickel and nickel-base alloys are used here because of their properties in withstanding corrosive environments and high temperatures, which is especially beneficial for a heat dissipation device. The reason why nickel has these properties is because of its 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 highly resistant to corrosion, so corroded material will not build up on the surface in the long run.
Otherwise, the base and heatpipes are composed of copper with nickel plating on the outside. Copper is used because it has one of the best heat transfer abilities with a thermal conductivity of 401W/mK. Meanwhile, the fins are made up of aluminum as it is quite a bit lighter in comparison to copper. This reduction in weight will reduce stress on the motherboard, although aluminum has a lower conductivity of 237W/mK, which is not as optimal for heat transfer, but the tradeoff is understandable.
The included fan with the Noctua NH-L12Sx77 is the NF-A12x15 PWM fan. This is a typical 120mm fan with a slim 15mm thickness. The thin profile is helpful to minimize the cooler's footprint as much as possible. The fan attaches with two small metal brackets, which hook through the fan holes and clips onto the fins of the heatsink. The fan features an SSO2 bearing, which should provide an excellent lifespan while keeping the fan quiet. The fan can reach speeds up to 1850RPM; less if the low noise adapter is installed. The airflow the fan generates is 94.2m³/h, while the noise it generates is 23.9dB(A). This fan should provide all the power needed to cool an average CPU.
Installing the Noctua NH-L12Sx77 is a bit of a hassle because of the small form factor. The directions for the installation are clear, providing you with all the necessary information, including different hardware for both Intel and AMD. Be careful to not use the incorrect screws or mounting hardware. For my AMD AM4 socket, installation was easy initially. The Noctua NH-L12Sx77 uses the backplate that comes with the motherboard. However, for Intel processors, you will need to use the included backplate. In the photo below, you can see that each mounting bar has two locations on each side for screws to find a home. The manual describes which ones to use to ensure proper contact with the CPU. These are to either install an offset position or the standard position. Each set of mounting hardware has this option to provide some flexibility depending on the case you have.
Flipping to the other side, for AMD motherboards, you can choose between two sets of mounting bars, depending on how you want to orient the cooler relative to the processor. It is important you do not mix and match these bars, but the rest of the screws and washers are shared for the AMD install. Afterwards is where the installation can get tricky. You have to align the cooler with the bracket around the CPU and then push the screwdriver through the fins, the fan, and into the screws to tighten it down. I tried to take the fan off first before mounting it to the arms, but this would require me to remove my memory modules, which would then be nearly impossible to install after the heatsink is in place. As such, this definitely takes a bit of time to line it all up. Even so, this type of installation is expected with coolers of this size. Before you do this, be sure to apply thermal paste on the CPU. Noctua has included their latest NT-H2 thermal grease, which is great to finally see come stock with their coolers. Overall, the Noctua NH-L12Sx77 is a great piece of hardware, and we will have to see how it performs on the next page.
Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Hardware; Installation
3. Test Results
4. Conclusion