Noctua NH-L9i Review – Ultra Low Profile Cooler for Intel CPUs

If you’re in need of a cooler that fits within super small form factor cases – such as a Mini-ITX case or a really small Micro-ATX, you would usually have to rely on the stock cooler. Intel’s stock coolers are actually quite good at stock speeds – they are small, and low profile, but can get a bit noisy and hot under load.

Noctua seeks to remedy that with a cooler that is just as small, but features a lot more dissipation area, and even has a pair of copper pipes to drive the heat from the bottom of the heatsink to the fins more efficiently. Today we’re reviewing the Noctua NH-L9i, compatible with LGA-1155, 1156, and upcoming LGA-1150 (Haswell) processors:

This little cooler is also available in an AMD version, dubbed NH-L9a. The Intel version we’re reviewing is designed for Ivy Bridge and Sandy Bridge CPUs with a TDP 65W or less generally, but can accommodate higher wattage CPUs with some provisions. For instance, when using a 77W or 95W TDP CPU (Core i5 and i7) it is recommended you disable turbo mode, ensuring that the enclosure is well ventilated, and the Low Noise Adapter is not to be used.

This tells us just what this heatsink is meant for – Home Theater systems using Core i3 processors. If you’re using a PC to stream video, or as a “Steam Box” with an auxiliary video card, that is all you’re ever going to need. If you are building a general purpose PC that needs more power, you’ll want to look at something like the still-low-profile Noctua NH-L12 to use with a Core i5 or Core i7.

Noctua NH-L9i Closer Look

As you know, we don’t like to waste your time trying to get pageviews by cutting and pasting specs that take up an entire page when you can just look at them on Noctua’s page.  Or check them out below:

The specs that stand out to me are the height – at just 37mm tall with the fan, this cooler can fit into very low profile cases such as the 2.67″ tall SilverStone LC19. And despite its low height, it still weights almost a pound! You will also note the generous 6 year warranty, and low acoustics of the fan when under operation.

One thing Noctua has going for it is their unique look when it comes to product design and packaging. In the cooling market, we’re so used to seeing garish colours and plenty of flashy design elements, so Noctua’s muted brown palette ironically makes their products stand out from the pack. They also do product packaging better than anyone else…

The NH-L9i is neatly packaged along with all the necessary mounting hardware (mITX screws are included) and a very well-designed manual that I believe is personally signed by Noctua CEO Roland Mossig. Also included is a small tube of their excellent NT-H1 thermal compound. The Low Noise Adapter lowers the max RPM from 1700 RPM to 1500, which makes the NH-L9i inaudible from any realistic distance.

The single purpose LGA-115x design allows for a very simple mounting mechanism. On the other hand, that single purpose means that you are stuck with that same CPU socket for the entire time you want to use this cooler. Thankfully, Haswell’s LGA-1150 socket is confirmed to have the exact same measurements, so it’s compatible with the upcoming CPUs from Intel. However if you want to switch over to AMD (whose FM2 APUs make for very good HTPC builds with integrated GPU performance totally capable for gaming on a TV), you will have to buy the NH-L9a version.

The bottom copper base is nickel plated, but does not feature a mirror finish we often see on high end heatsinks. There is are visible machining marks in the finish, but the grooves shouldn’t pose a problem once thermal paste is used.

Noctua NH-L9i Installation

As you can guess, a CPU cooler designed for a single socket type has a very simple installation. Simply screw in the bolts from the back of the motherboard:

I have to say though – I hate installing heatsinks this way. It is rarely easy to keep the heatsink in place while fumbling around the back of the motherboard to install the screws, and I definitely would have preferred removing the fan and installing the screws from the top. That being said, the NH-L9i is small enough that installation wasn’t too bad in this case. We will be reviewing another heatsink soon that has a similar method that was much more of a pain to install.

Noctua NH-L9i Performance

Performance testing will be about as simple as it gets. It wouldn’t serve anyone to test with a CPU this wasn’t designed for, so we’re going to use a Core i3 2120 for testing. At 65W TDP, this CPU sits at the top of Noctua’s TDP guidelines that do not require having to disable features or worry about ventilation. We will be testing it against the stock Intel Core i3 heatsink (this is the one without the copper base).

To test CPU cooling performance, we ran LinPack x64 for 30 minutes. Temperatures of core0 and core1 are read from the onboard monitor, and the average of the two is recorded. Testing was done on an open bench, with an ambient temperature of 23 celsius. Coolers were left in auto PWM mode, which had the NH-L9i running at 1700 RPM at full load, and 1500 RPM with the LNA (simply a resistor which lowers the voltage to 8v). The Intel cooler ran at 1300 RPM at full load.

Noctua’s included NT-H1 thermal paste was used for the NH-L9i cooler, and Intel’s pre-applied thermal paste was used for the stock cooler.

With the fans running at auto speed, the Noctua NH-L9i easily outperformed the Intel cooler in our test. Interestingly, there is little penalty for using the LNA when used within the 65W TDP guideline.

To test sound levels, we placed an analog sound level meter exactly 7 cm from the side of the heatsinks, in a position that was not affected by turbulence.

Since sound pressure is on a logarithmic scale, and anything below 50 dB at 7 cm can likely be considered as “effectively silent” that is the starting point to this graph. Keep in mind that a few decibels on this scale actually means it is considerably louder:

Since we consider 50 dB at 7cm to be “zero” that’s where this chart begins. And at that point, the NH-L9i is “zero” while the other two are 4-5 dB above that level. I was actually surprised by the ability of the Intel cooler to remain silent. At full speed, its fan only reaches 1300 RPM. The tradeoff of course is lower cooling performance, which would be made even worse inside a case.

Conclusions

Recommended Silent Hardware: Noctua NH-L9i

As you’d expect, a CPU cooler with such a specific goal is going to have a somewhat short review. The NH-L9i is specifically designed for ultra slim cases in the 2.5″ height range, mostly mITX cases for HTPC use or ultra SFF like the M350. While the Intel stock cooler could be used in this case, you don’t get the “Phanteks Experience” that way. That means silent operation without giving up cooling performance, and solid reliability over many years.

Whether it’s worth the hefty $50 price tag is up to you to decide. Builds requiring such a specific type of cooler are generally considered high-end, so in that case it may be worth it. If the NH-L9i fits your specific needs, and you have the cash to spare, you won’t be disappointed in its performance, that’s for sure.

If you can accommodate a slightly taller heatsink on a mATX motherboard that doesn’t place the PCI-E slot right next to the CPU socket, you might want to check out the Noctua NH-L12 instead. It is more suitable for cases in the 4″ high range.