By – John Williamson

Noctua Fans Review

Noctua have recently expanded their small form factor cooler line-up in lieu of growing demand for compact cases and custom-made Steam Machines. In addition to the NH-L9i M-ITX cooler, you can opt for the NH-D9L or NH-U9S which offer silent operation and low temperatures providing you stick to conservative voltages. These units are extremely easy to work with due to their size and excel when you factor in widespread RAM compatibility and PCI-E x16 clearance on M-ITX motherboards. Overclocking potential is still fairly limited as the heatsink’s surface area cannot dissipate large amounts of heat in an effective manner. Nevertheless, the 95x95mm design and superb NF-A9 premium fan results in a staggering size to cooling performance ratio.

The NH-D9L and NH-U9S arrive in similar packaging which evokes a luxurious feel. Noctua have become synonymous with their attention-to-detail and this is shown throughout the unboxing process. On the exterior is a succinct synopsis of the product and clear diagrams explaining how the heatsink is constructed. Once opened, the top layer features a organized tray of accessories including the Secufirm2 Mounting System, NF-A9 clips (for an additional fan), NT-H1 premium thermal compound, screwdriver, Low Noise Adapter, metal case badge, installation guide for 115x, 2011, AM2 and fixing screws. Everything is separated into cardboard compartments and there are images outlining what is included. This design is marvellous and makes the installation less daunting for first-time builders. I would prefer to see a Y cable included or an extension but that would add to the overall cost. Also, the Phillips screwdriver is solid and made from rigid metal instead of the thin plastic screwdrivers bundled in lower quality kits.

Taking out the NH-D9L was effortless as Noctua surrounds the heatsink in a cardboard frame and attaches two pieces to the top and bottom. The top section has two indents for your fingers to easily pull the cardboard off and uncouple the cooler. While this was extraordinarily simple, I was quite disappointed with the NH-U9S because the heatsink is in the open and cushioned with one cardboard part instead of easy to pull tabs. I actually ended up ripping the cardboard by accident on one side and had to force it out. Despite this, the thick grade of cardboard offers impeccable protection during transit and ensures the 92mm fan doesn’t get dislodged. Once again Noctua’s packaging sets a very high standard and one that other companies should take note of.

Discussing the aesthetical qualities of a Noctua product is usually quite a polarizing topic. As you might expect, Noctua have maintained their signature brown and cream colour scheme and I personally find it tolerable. While it’s not the most spectacular design, I do feel it looks professional and instantly identifies a cooler made by Noctua. Modern day enthusiasts predominantly build PCs with a windowed side panel and focus on a particular colour. If Noctua were able to create two SKUs; one for the traditional setup and another for ostentatious builds with an RGB LED fan, they might conjure up way to appeal to a different sector of the market.

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There is a slight variation in the install process depending on which cooler you purchase. With the NH-L9L, the heatsink is manufactured in one complete piece with a fan attached to either end. In contrast to this, the NH-U9S utilizes two smaller metal sections with a fan in the middle. During the install, you need to remove the fan to access each cooler’s mounting screws. Noctua only uses hardened, metal materials with the mounting hardware which makes it the easiest aftermarket heatsink to install.

The first step is to feed the backplate through the CPU cutout and position a plastic washer over each bolt. Then attach the two mounting bars and gently turn four thumbscrews. Before you tighten these screws, double check that the bars are facing outwards and in the orientation you want the cooler to sit. After this, apply a small amount of thermal paste, uncouple the fan and tighten two screws next to the CPU plate. Once complete, ensure the cooler is straight and secure, then re-attach the included fan before plugging in the fan’s 4-pin cable.

Before we get into the performance numbers, it’s vital to differentiate between these two models. The NH-D9L as its name suggests employs a D-shape cooler with 4 nickel plated copper heatpipes while the NH-D9S has greater thermal dissipation due to 5 heatpipes. By default, both products come with a 92mm NF-A9 fan which operates at a maximum rpm of 2000 and pushes an airflow figure of 78.9 m3/h at 22.8 dbA. When you connect the Low Noise Adapter, the rpm speed is restricted to 1550 with an airflow of 62.6 m3/h at 16.3 dbA. Additionally, the AF-A9 outputs 2.28 mmH2O of static pressure and 1.53 mmH2O using the L.N.A. This equates to a significant amount of airflow at an incredibly small acoustical noise.

In theory, you could purchase a second NF-A9 fan to aid cooling and allow for a better overclock but it seems rather superfluous for smaller builds. I could understand going down this route with the NH-D15, but you are still going to be limited by the heatsink surface. The testing results confirm this hypothesis when attempting an overclock at 4.4GHz, and 1.289v whilst running an extreme load cycle in OCCT. At stock settings with an i7 4770K, the NH-D9L achieved an idle temperature of 32C, whilst the NH-D9S managed 28C. Under heavy strain, these figures dramatically increased to 74C and 66C. I did attempt to attach a second fan on the 5 heatpipe cooler to see what difference this could make. Unsurprisingly, the impact was only 3C and didn’t offer much in terms of value when you consider the performance effect.

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Onto the overclocked results; I initially opted for 1.3v at 4.5GHz but the NH-L9L was extremely close to failing due to a 93C temperature and began thermal throttling after 3-4 minutes. As a result, I reduced the core voltage down to 1.289v with the CPU clocked at 4.4GHz. Load temperatures for the NH-D9L and ND-U9S were 83C and 77C with a 4C reduction when using dual fans. These statistics are still relatively high and might be a concern for those who want a 24/7 overclock which can withstand changes in seasonal temperature.

My recommendation is to either run the NH-D9L with the Low Noise Adapter and have a beautifully silent HTPC.or opt for a small overclock on the NH-U9S at around 4.3GHz, trying to hit the lowest voltage required whilst maintaining a stable desktop. Haswell needs extremely powerful cooling to tame large voltages and only a few coolers can do it such as the Swiftech H220, Corsair H110 and custom loops. I will say though that being able to even attain a small overclock is staggering given the heatsink’s tiny size.

In addition to cooling proficiency, I analyzed the noise output to see how obnoxious the fan curve was under high temperatures. The NH-D9L hit a maximum threshold of 38 dbA and an average of 36 dbA whilst the NH-U9S reached a max of 36 dbA and average of 34 dbA. Interestingly enough, there wasn’t a huge gap between the idle and load noise states which makes both coolers a fantastic investment for a quiet gaming PC. To summarize the performance; I am mightily impressed with the audible levels which are completely silent whilst hitting good temperatures and a small overclock. It’s also important to reiterate that CPU overclocks don’t have a monumental effect on frames per second and this should be minimized further in DirectX 12.

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Conclusion – Is It Worth Your Money?

The NH-D9L and NH-U9S are another fine example of Noctua’s unbridled commitment to provide superlative performance whilst maintaining silent running. While the overclocking potential is fairly small, you have to appreciate that Noctua have done everything possible to eek out performance in such a limiting form factor. The NH-U9S is better suited to heat dissipation due to the 5 heatpipe design so I would recommend that for heavier usage. In practical terms, either of these coolers would be a perfect accompaniment to a M-ITX or mATX build.

Noctua NH-D9L and NH-U9S CPU Cooler Summary:


  • Time Used – 26 Days
  • Software Used – OCCT, HWMonitor, CoreTemp
  • Acquisition Method – Review Unit
  • Availability – Newegg, Amazon
  • System Specs – Intel I7 4770K, 16GB RAM, Gigabyte G1 Gaming GTX 980
  • Compatibility – Intel LGA2011-0 & LGA2011-3 (Square ILM), LGA1156, LGA1155, LGA1150  & AMD AM2, AM2+, AM3, AM3+, FM1, FM2, FM2+ (backplate required)

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