Noctua NH-L9i Low Profile Review



With demands for CPU coolers being at an all-time high, everyone ranging from consumers all the way down to business customers have different criteria to meet.  From the needs required to cool the monstrous Intel i7 4770k, all the way to i3’s and Pentiums, there are a host of options available to cover the entire spectrum of CPU’s available.

Noctua are one such company, with their legendary DH-14 cooler, they led the market on high performance CPU coolers for a long period of time, only recently being dethroned by the introduction of the all-in-one CPU liquid coolers.

At one end of the spectrum are the low profile coolers and today I will be taking a look at Noctua’s latest low profile offering which is only designed for use on Intel’s LGA 115X socket, the NH-L9i, will it put a dent in the big boys of cooling, or is it only suited to HTPCs and the like?  Let’s find out, starting with some specifications…

On the front of the packaging, we have Noctua’s usual dark brown and white colour scheme.  Also present is the model number and a small list of the coolers features.  This cooler in particular is only compatible with Intel’s LGA 115X series, which includes 1156, 1155 and 1150.

Displayed on the rear of the box, is more information regarding the cooler in a multitude of different languages which includes English, German, French, Spanish, Portuguese, Russian, Japanese and Chinese.  The inclusion of Chinese in my opinion is good, as the world’s most spoken languages are covered.  In the bottom right hand corner, there is a picture illustrating the measurements of the NH-L9i itself.

Upon opening the box, I was greeted with a very well presented layout which consisted of different compartments, one for the mounting screws, one for the fabulous Noctua NT-H1 thermal paste, a fan resistor to change the power of the fan (which makes it quieter), the NH-L9i cooler itself and a hard backed Noctua badge.  In the top of the box there is an instruction manual.

I have to say I am a big fan of the packaging, much better than just throwing a packet of screws into the box, it shows Noctua take their packaging seriously and that’s something I endorse.

Taking a first look at the NH-L9i cooler, it’s dinky….some would say it looks too small.  Personally this would be a perfect solution for those looking for a very low profile cooler.  It’s so small I can literally wrap my big hand all around it.

The fan colour keeps in tradition with Noctuas beige like presence which some love and some hate, me being slightly on the fence as I prefer performance to design.  The fan comes provided pre mounted to the cooler by the way of 4 screws.  This not only saves time, but once again shows that Noctua are serious when it comes to providing the full package.

On the flip side of the cooler as you can see, the mounting mechanism is clearly displayed.  Aside from the fan cable coming out you have the heat sink itself, which is very small but given it’s a low profile design, this is to be expected.

Looking at the NH-L9i from the side, it really is apparent how small and dainty this cooler is.  The Noctua logo is etched into the metal which is a nice touch and everything looks very compact and in my opinion, stylish.

Installation of the Noctua NH-L9i was as easy as could be.  Being low profile, this meant it wasn’t like trying to install an engine in a Ford Focus, but more a simple task like slotting a piece into a jigsaw.

To start with it was a simple case of applying Noctua’s thermal paste, which I use for all cooler reviews anyway.  Next I placed the cooler over the socket ensuring the mounting screw holes matched up with the socket holes on the motherboard, which in this case is LGA 1150.

As you can also see here, none of the DIMM slots for the memory are covered, so it allows you to use any RAM you wish to and aren’t limited by the height of the heat sinks.

Once the first step is completed, on the rear of the motherboard, all you have to do is take the 4 mounting bolts and feed them through the motherboards mounting holes.  To ensure you have the screw lined up with the mount it takes a quick check to make sure it’s aligned, but once you have them aligned, screwing them into place takes seconds.

This is easier as there is no mounting plate to worry about, it also allows more air to the rear of the socket in my opinion to aid with cooling.

After step 2, simply turn the motherboard over, in this case it’s the ASRock Z87 Extreme3, and voila, installation is complete, other than making sure the fan cable is plugged into the relevant header on the motherboard.

Once again from the top down view, there is no obstruction of the RAM slots.

With the installation complete, it’s now time to see how the NH-L9i performs, let’s move onto the test setup, then the performance…

CPU – Intel i7 4770k

Motherboard – ASRock Z87 Extreme3

Memory – Patriot Viper3 8GB (2400MHz CAS10) 2x4GB

Graphics – HD 4600 325/1200MHz

Cooler – Noctua NH-L9i

Storage – Western Digital 320GB Caviar Blue (7200RPM 8MB Cache)

To test the capability of the coolers, our testing methodology is simple.  We measure the temp after 10 minutes on idle, both at 3.9GHz which our samples stock turbo boost speed and with an overclock of 4.5GHz.  To test the loaded temperatures I use prime95 and its torture test for 10 minutes and record the max temperature given.

Any time a cooler hits 100c on any test, it is automatically classed as a fail, simply due to the extreme temperatures which aren’t good for 24/7 systems.

Noise levels are tested with a decibel meter approximately 1 inch away from the cooler and the readings of the noise levels are taken when the coolers are in idle and loaded states.  The background noise during testing is very minimal and not enough to disrupt the readings given.

Now it’s time for my final thoughts on the Noctua NH-L9i Low Profile CPU Cooler designed for socket LGA 115X CPU’s, how does it compare to its bigger brothers and how does it cope with the extreme heat of Haswell combined with a nice hot summers day?

Well starting with the thermal performance, other than the low profile design and the how small the NH-L9i actually is, you would be hard pushed to tell the difference between one of these and a full tower cooler at idle.  On the other hand when you put full load on the NH-L9i, this is when you can see the coolers small size come into play.  At idle, the NH-L9i is actually cooler than the Noctua NH-U12s which is an amazing feat by my standards.  Even at 4.5GHz, the idle delta temperatures are great in comparison to the Noctua NH-U14S, which is currently one of Noctuas flagship CPU coolers.

Taking that into consideration, the overclocked results are slightly different, with the NH-L9i starting to show its limit, but it still does better overall than the Enermax ETS-T40 CPU cooler, in every test.  In terms of performance for what is currently only design for low profile PC’s, I have a little monster on my hands.

In my noise performance tests, it was a very similar story; the NH-L9i was pretty much the same in terms of noise levels at idle compared to its bigger counterparts.  At load, it made a considerable bit of difference, but this is clearly down to the small size of the fan.

Moving on to the aesthetics, the cooler is so small, it looks neat and if you like Noctuas usual beige colour schemes, then you pretty much have the full package.  Do I wish they would start making black fans for their CPU coolers?  Yes, and I think I speak for quite a large majority in this regard.

Overall the Noctua NH-L9i, packs a pretty powerful punch and for it small stature, is limited only by high overclocks.  Bearing in mind that the heat the i7 4770k Haswell CPU generates at speeds like 4.5GHz is pretty insane; it shows just how good this cooler is.

I still feel its main strength lies in a HTPC, given that its socket LGA 115X of course.  The performance speaks volumes really and shows that Noctuas engineering is literally second to none.

One thing I would like to see, is a variant that can be used with AMD CPU’s and other sockets, as not everybody buys Intel LGA 115X CPU’s.

The price is another good point, coming in at just under £35, you have a cooler that’s not just capable, but very versatile in the way it will fit into any case, allowing you to use all the available RAM slots on the motherboard.  If I was looking for a low profile cooler, the Noctua NH-L9i would be at the top of my list.

Thanks to Noctua for the sample and I look forward to more of their products in the near future.

  • Performance
  • Design
  • Value


The Noctua NH-L9i is certainly worthy of being not only considered for Media Centers and servers, but for mainstream systems. If you aren’t planning on overclocking your CPU to the hilt, then this cooler could just be the one you are looking for; if you are on socket LGA 115X of course.


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