Noctua NH-L9x65 CPU Cooler Review – Compact and Quiet


At Technology X, we test our CPU coolers slightly different depending upon the cooler’s marketed purpose, whether it be for a silent operation or extreme overclocking.  Our goal is to test in a system that has been optimized with our SSD Optimization Guide, however, CPU C State alteration may or may not have occurred depending on the motherboard and BIOS configurations. Additionally, we also try to include links to the benchmarks used in our report so that you as the reader can replicate our tests to confirm that your cooler performs the way it should.


All of the components we use for testing are standard off-the-shelf PC components from major manufacturers, which can be purchased at a variety local retailers and online. We’ll also provide links to our components for those of you that find an interest in our equipment.


We’d like to thank Intel, ASRock, and Crucial for providing vital components in this test bench, without which this report would not be possible. Check out our review of the Intel Core i7 5960XASRock X99 OC Formula, and the Crucial Ballistix Elite DDR4-2666 memory kit, used  in this report.

PC CHASSIS: Thermaltake Core V51
CPU: Intel Core i7 5960X @ 4.2GHZ OC
MEMORY: 16GB Crucial Ballistix Elite DDR4-2666
POWER SUPPLY: Corsair TX850 v2


In order to test our CPU cooler, we’ll be running a CPU stress test and monitoring our temperatures using AIDA64, which is a great utility for benchmarking, testing the stability of, and monitoring your system.


To test our cooler, we ran AIDA64’s ‘System Stability Test’ for 1 hour and recorded the highest temperature reached on any core. We did so at both the stock core frequency of our Intel Core i7 5960X, as well as overclocked to 3.6GHz, and 4.2GHz.

During all tests our ambient temperature was approximately 23.8C while the cooler’s intake temperature was a slightly warmer 28.4C


At 4.2GHz we can see our CPU gets dangerously close to our CPU’s Tj. Max, which is definitely not good for long-term use, however this is to be expected with a cooler of this size and price. However, looking at our stock and 3.6GHz results we can see a much different result. With idles of 36, and load temperatures of 72, and 79 which at the highest is only 50.6C over the cooler’s intake air temperature, this cooler performs very respectably. While we wouldn’t necessarily recommend it for cooling Intel’s most power-hungry CPU, it clearly isn’t out of the question.


We tested the cooler’s noise output by using a sound meter placed one meter away from the system’s case with the side-panel closed. We tested the cooler at both full speed (2500 RPM) and an idle speed of 1,000 RPM. We also tested the sound of our overall system’s cooling without the cooler’s fan turned on to illustrate the difference. That result was an average of 29 dB.


For noise, we found this thing to be whisper quiet. At idle, it was virtually undetectable over the rest of our system, and even at full speed it was barely noticeable, unless we were really looking for it. This thing is silent!


With small form-factor machines such as Steam Machines, HTPCs, and other mini-ITX based systems becoming more and more popular, the market for compact and low-profile coolers is larger than ever. While, there are plenty of options on the market, few give satisfactory cooling performance without making compromises on design.


Fortunately, in our time with the Noctua NH-L9x65 we can say that it is without a doubt, a no-compromise compact cooling solution. While it may not perform as well as the larger alternatives, it does perform well enough to keep just about any CPU cool, within reason. It does all that while keeping the footprint down to 95mm in diameter and a tiny 65mm tall, thanks to its ultra low-profile fan design.

While pricing may be a little high, the overall package is well-worth it, if size is the number one concern. We’d have no problem recommending the Noctua NH-L9x65 to anyone in the market for a compact, low-profile and silent cooling solution. With that, we’re proud to award it with our Technology X Silver Seal!

Tech X Silver Seal Opt

Check out the Noctua NH-L9x65 on Amazon Today!

In our review of Noctua's latest flagship, the NH-D15, we proclaimed it the king of air coolers, for its massive cooling performance and silent operation. However, while the NH-D15 is the definitive solution where space is not a concern, it is definitely not the end all be all, especially for those looking for a cooler for their small form-factor systems. Mini-ITX users fear not, as Noctua also has a solution such situations as well. The company's NH-L9x65 promises an ultra compact design, as well as Noctua's signature silent operation, but can it keep even the most demanding overclocks cool? Let's…

Review Overview

Build Quality

Slim Cooling!

The Noctua NH-L9x65 is a slim, low-profile CPU cooler that doesn't lack on performance! A recommended buy in our books!

User Rating: 4.28 ( 2 votes)


  1. Why did you test this on a X99-based system? It seems to me this wouldn’t be the target platform so such a cooler. It’s certainly a worst-case scenario but it probably makes more sense on lower-power part, IMO. I have the NH-9Li version which works great on a i7 4770.

    • This is our standard test bench for cooler tests. Also, as the 5860x does draw more power and create more heat it is the worst-case scenario as remember these coolers will be used in smaller, tighter places that can be much hotter that our relatively open testbench.

      If it can cool the 5960x to comfortable temps, it can cool any Intel chip at even higher clock speeds.

Leave a Reply

Your email address will not be published. Required fields are marked *