Noctua NH-L9i Review

ccokeman - 2012-03-01 13:30:22 in CPU Cooling
Category: CPU Cooling
Reviewed by: ccokeman   
Reviewed on: January 23, 2013
Price: $47.99

Noctua NH-L9i Introduction:

Many of us are running our systems out of spec, with advanced high end cooling solutions(Air or Liquid) to keep the thermals generated by our processors in check. The stock solution might be fine at stock speeds, but just doesn't hack it when upping the clock speed. Fine being the operative word here. But, what if you are just looking for better than OE cooling or want to place your processor in a mini ITX board and enclosure? You need a cooling solution that not only fits like the OE solution, but offers improved thermal margins when slapped into that small build. After having looked at another small form factor solution that offered much better thermal performance than the OE cooling, it was time to see if the folks at Noctua had a viable solution to the problem of how to manage the thermal load, for the user looking to build a small form factor system. For that purpose Noctua has the NH-L9i, a low profile 37mm tall high performance cooling solution, built for use in situations where cooler clearance is tight. With this model, there are no clearance issues for DRAM or PCIe cards, it uses Noctua's patented SecuFirm 2 mounting system, is built for a 65w TDP load, and comes with a 14mm thick highly optimized PWM fan. Priced at a less than modest $47.99, the Noctua NH-L9i offers up a quiet package that should cool well based on specifications alone. Lets dig into it and see what Noctua has put together.

NH-L9i Closer Look:

The packaging is pure Nocuta. If you don't know what that means, you get the clean brown, blue, and white coloring with a wealth of information covering just about every panel. When you purchase at a brick and mortar location, this enables the consumer to make an informed buying decision based on the information presented. The sides display the features and technical specifications, while the back gives a short synopsis of the coolers uses and features.











Internally, Noctua carefully packs up the components so they are held in place and easy to identify. A foam block holds the NH-L9i in position, also holding a metal case badge, the Low Noise fan adapter, NT-H1 thermal compound, and the socket 115X specific components of the SecuFirm2 mounting solution. A detailed set of installation instructions are neatly tucked into the bottom of the lid, so it is front and center when you pop open the package. When you look at the accessory bundle, all of these things are present with the addition of a longer set of screws to mount one of Noctua's 92x25mm thick fans for higher airflow. A nice addition if you have more than 40mm of room above the socket to improve cooling capacity.



In the past, I have looked at a broad cross section of Noctua product stacks and been impressed by what they have to offer. If this low profile solution is not up to the task, I would be shocked. Lets see what the NH-L9i has to offer for the user looking for the upper tier low profile cooling solution.

Noctua NH-L9i Closer Look:

Measuring 95 x 95 x 37mm the NH-L9i is a small solution, for use in small form factor cases with Mini-ITX form factor Intel based motherboards, where space for a cooling solution is at a premium. Small in size the NH-L9i has some mass to it at 420g installed. This mass comes by way of the nickel plated copper base and dual heat pipes. The joints between the aluminum fins are soldered for both a more secure connection and to improve the transfer of the thermal load between the base and fin array. Removing the NF-A9x14 PWM premium fan drops the installed height to just 23mm. The small overall footprint ensures that there are no compatibility issues with even the largest DRAM modules and video cards.















Looking through the aluminum fin array, you get a look at the U shaped heat pipe configuration and can see just how much area the pair of heat pipes covers, which contributes to the efficiency of the cooler. The bottom of the NH-L9i illustrates how the SecuFirm2 mounting solution connects the cooler to the board. The base comes covered with a vinyl cover to eliminate any scarring to the contact plate. The base on this cooler was smooth to the touch with very fine machining marks, fine enough that they cant be felt when running a fingernail across the base.




Noctuas NF-A9x14 PWM fan is used to provide the airflow needed to shed the 65w load this cooler is designed to handle. This fan is what makes the the cooler work. It is 92x92x14mm thick and uses all of the technology at Noctuas disposal. Rated for operation between 300 and 2200RPM, Noctua uses a custom designed PWM IC that uses "Smooth Commutation Drive" technology for a no noise solution at lower fan speeds. An AAO (Advanced Acoustic Optimization) frame is used to house the fan. This frame features integrated vibration dampeners on all four corners, has a stepped inlet design to induce turbulence into the fan reducing noise and improving intake flow, and uses micro structures to reduce flow separation from the blades, again improving the flow and noise characteristics of the fan. The blade assembly uses a self-stabilizing oil-pressure bearing (SSO-Bearing) to keep noise imparted by the bearing assembly to a minimum, by using a large magnet to stabilize the assembly. Flow acceleration channels are used on each blade to minimize suction side airflow separation by speeding up the airflow along the outer edges of the AAO frame. The wiring is encased in a rubberized sleeve that not only looks good, but features excellent longevity. All of this gets you a fan with airflow ratings of 30 C.F.M. at 23.6 dBA with a static pressure of 1.64 mm H2O. A MTBF rating of greater than 150,000 hours is well beyond the 6 year warranty period for that extra piece of mind.




Installation of the NH-L9i is about as simple as it gets, but does need both hands to get it installed. If your chassis has an open access port, you can install it with the motherboard already secured in the chassis, but if not it will require the board to be out on the bench. Either way, apply the NT-H1 thermal compound and hold the cooler in position against the CPU. Then put the back plate in place and start all four of the SecuFirm2 screws. Continue tightening the screws in an X pattern until seated. Once seated, plug the 4 pin power connector onto the CPU fan header on the motherboard and it's off to the races. As you can see there is nothing on the NH-L9i that will cause a space concern with the DRAM or any device used in the top PCIe slot.



Noctuas NH-L9i is a well built cooler that makes the most of the design and technology behind it. Rated at only 65w lets see how it handles the 95w TDP Core i7 2600K .

NH-L9i Specifications:

Socket compatibility
LGA1150, LGA1155, LGA1156                     
Height (without fan)
23 mm
Width (without fan)
95 mm                 
Depth (without fan)
95 mm
Height (with fan)
37 mm                 
Width (with fan)
95 mm
Depth (with fan)
95 mm
Weight (without fan)
345 g     
Weight (with fan)
420 g
Copper (base and heat-pipes), aluminum (cooling fins), soldered joints & nickel plating
Fan compatibility
92x92x14mm, 92x92x25mm
Scope of Delivery
NF-A9x14 PWM premium fan
Low-Noise Adaptor (L.N.A.)
NT-H1 high-grade thermal compound
SecuFirm2™ Mounting Kit
Screws for 92x92x25mm fans
Noctua Metal Case-Badge
6 Years
Fan specifications
Noctua NF-A9x14 PWM
Max. Rotational Speed (+/- 10%)
2500 RPM
Max. Rotational Speed with L.N.A. (+/- 10%)
1800 RPM
Min. Rotational Speed (PWM)
300 RPM
Max. Airflow
57,5 m³/h
Max. Airflow with L.N.A.
40,8 m³/h
Max. Acoustical Noise
23,6 dB(A)
Max. Acoustical Noise with L.N.A.
14,8 dB(A)
Input Power
2.52 W
Voltage Range
12 V
> 150.000 h


NH-L9i Features:



All information courtesy of Noctua @

Noctua NH-L9i Testing:

Testing of Noctua NH-L9i low profile CPU cooler will be accomplished by installing the cooler into the test system mounted into a case not a test bench. Most systems are built and mounted into a sealed (relatively) chassis so this method will be used to generate the load and idle results to give a real world view as to what kind of cooling performance one can expect based on the test system listed below. Of course your results may vary due to case design and ambient air temperature by several degrees. The CPU load is generated by Prime 95 version 27.7 for a period of 2 hours, with a cool down period of one hour after the computer has returned to an idle state. Real Temp 3.70 is used to log the temperatures over the time frame, with the highest and lowest averages across the four cores of the Core i7 2600K test CPU. Ambient temperatures are kept at 24C throughout the testing to minimize the impact of a variable temperature. Each cooler is tested with the manufacturer supplied thermal compound as delivered. Many of us have our own TIM favorites, but for the end user without a half dozen tubes of thermal paste laying around, the supplied TIM will have to do and is how these coolers will be tested.

Testing Setup:


Comparison Coolers:






At stock speeds and voltages on the Core i7 2600K processor, Noctua's low profile NH-L9i was able to deliver a solid 13+% improvement of 10C, over the 73C load temperature delivered by the Intel box cooling solution. On top of that, it shaved 4C off the load temperature delivered by the the other low profile cooler in this comparison, the Phanteks TC90LS. With only a 65W TDP load capacity, these temperatures are a solid improvement when run on a higher wattage CPU than it is rated for. The other low profile solutions in the comparison failed to keep the CPU temps in check, with my overclocked settings. 96C is in no way kept in check, but at least Noctuas design kept the load temperature under 100C. It's not recommended to run that close to the TJ Max temp, but it was able to stay under that limit without throttling.

Noctua NH-L9i Conclusion:

A cooling solution for the overclocking enthusiast, the NH-L9i is not. Although some mild overclocking with a low wattage TDP processor might open some doors for this low profile solution. As it is, the Noctua NH-L9i plays well above its fighting weight when cooling a 95w TDP chip. Keeping that in mind the NH-L9i was able to deliver a 13+% improvement over the stock Intel box cooling solution when paired with my Core i7 2600K and it even out performed a competing solution by 4C running in the same configuration. Impressive to say the least from a 92x92mm cooler that stands only 37mm tall. As a low profile design, the NH-L9i is going to fit into a chassis that larger cooling solutions just cannot fit into. Perfect for a small form factor gaming rig or HTPC where space is at a premium. The compact footprint means you will not run into some of the challenges seen with larger solutions, that include fitment problems when running DRAM modules with large heat shields or space concerns with video cards that just get to close to the cooler. While this specific cooler is going to work only with Intel LGA socket 115X motherboards and processors AMD fans are not left out in the cold per say. Noctua makes the NH-L9a with socket compatibility for all current AMD sockets.

For $48 you get a cooling solution that just says quality through and through. A smooth base, well thought out mounting solution, nickel plated copper base and heat pipes, excellent thermal compound, low noise adapter, and a fan that is packed full of technology to reduce noise and increase static pressure and airflow, both desirable traits in a cooling solution. Low noise cooling is where Noctua excels. You get all this, a 6 year warranty, and more with the NH-L9i. So far, this is the best low profile small form factor cooler I have tested.