Noctua NH-L9i Low Profile CPU Cooler Review

1. Introduction2. Packaging & Bundle3. The Noctua NH-L9i CPU Cooler4. Testing Methodology5. Thermal Performance6. Acoustic Performance 7. Closing Thoughts8. View All Pages

Space constraints and component clearance can always present a major headache for Small Form Factor and mini-ITX users who want to improve their CPU cooling performance. Can Noctua's minute NH-L9i CPU cooler help to address these issues?

Measuring in at just 95 x 95 x 37mm, the Noctua NH-L9i is best suited to confined environments where space constraints can pose a major issue, such as inside a Small Form Factor case or mounted on a mini-ITX motherboard. Not just happy with usable dimensions, Noctua aims to offer SFF users a worthwhile cooling upgrade with the NH-L9i's 2500 RPM fan and 24mm, densely-packed fin array.

In the NH-L9i, has Noctua designed a cooler which proves that bigger isn't always better?

Specifications:

• CPU Socket Compatibility : Intel LGA 1155/1156 (Separate AMD variant available).
• Dimensions (without fan): 95 x 95 x 24mm.
• Dimensions (with fan): 95 x 95 x 37mm.
• Fan compatibility: 92mm (both 14mm and 25mm thickness).
• Fan Speed: 2500 RPM (1800 RPM with L.N.A.).
• Fan airflow: 57.5 m³/h.
• Fan Connector: 4-pin PWM.

Some of the key features of Noctua's NH-L9i CPU cooler are stated on the box's front side, such as the fan model, RAM compatibility and low-noise adapter. The NH-L9i's 37mm height is outlined via a silver sticker.

A multi-lingual piece of advertising is located on the packaging's rear side as well as an image of the cooler that is annotated with dimensions.

The Noctua NH-L9i bundle consists of a tube of NT-H1 thermal paste, a low-noise adapter (L.N.A.), installation hardware, a Noctua case badge and the installation manual. When using the L.N.A., the NF-A9x14 fan's speed is throttled to 1800 RPM in favour of quieter operation.

The Noctua NH-L9i colour scheme is very similar to that of any other Noctua cooler. Some consumers dislike the beige and red colours, while others think it creates a unique appearance.

Noctua uses a 14mm-thick, 92mm NF-A9x14 PWM fan which is capable of up to 2500 RPM operational speed with an airflow rate of 57.5 m³/h and acoustic output of 23.6 dbA.

Two sides of the NH-L9i's heatsink are closed to help maintain appropriate air pressure inside the fin array. Noctua embosses its company logo onto the outer metal plate. The heatsink's remaining two sides are left open to align with the natural path that the heat-saturated escaping air will take.

Noctua states the NH-L9i's height as 37mm with the fan, which is correct when the cooler is sat on a CPU, taking the CPU heatspreader as a reference point. When not installed, we measured the height to be 43mm – the 6mm increase due to the pre-installed mounting bracket.

As the Noctua NH-L9i CPU cooler only supports LGA 1155 hardware, Noctua pre-installs the necessary mounting brackets to reduce the consumer's installation time.

Comparable in terms of width and length to the Intel i5 3570K stock CPU cooler, the Noctua NH-L9i's reduced height makes it a good choice for users with inconvenient space constraints.

Noctua bases the NH-L9i's 95 x 95mm width and length dimensions around Intel's specified ‘keep-clear' socket zone to avoid unnecessary interference with components such as graphics cards and RAM.

Thanks to the pre-applied mounting brackets, installation was a fast procedure. Noctua directs users to apply thermal paste, mount the cooler and then secure it from the motherboard's rear side. This is a tricky procedure that had us crying out for an extra hand.

Once installation was finished, the Noctua NH-L9i was very securely attached to our motherboard. The low-profile design and narrow dimensions all but eliminate clearance issues with RAM, VRM heatsinks and other motherboard components.

Due to the very small height and secure installation of Noctua's NH-L9i CPU cooler, shipping a system with this heatsink pre-installed shouldn't cause any damage or movement worries.

Thermal Performance Test Procedures:

• Idle temperatures are obtained after sitting at the desktop for 15 minutes.
• Load temperatures are obtained after running Prime95 in the ‘Small FFTs' mode for 15 minutes.
• We repeated testing with our CPU overclocked to 4.0GHz (40x multiplier, 100MHz base clock) using a BIOS-set voltage of 1.200V.
• The cooler's fan(s) are set to 100% to eliminate inaccuracies due to dynamic PWM fan speed adjustments.
• The supplied thermal paste is used to provide an accurate interpretation of the cooler's out-of-the-box performance.
• We use HWMonitor to measure the CPU temperature.
• CPU temperature recording is accurate to +/- 0.5°C.
• Ambient temperature recording is accurate to +/- 0.05°C.
• Ambient temperature was maintained at 19°C.

Acoustic Performance Test Procedures:

• We measure the noise output of our entire system from a distance of 1m while the CPU cooler's fan(s) operate at 100% (indicating the maximum noise output).
• We set the case fans to minimum speed (hence noise) and avoid using a discrete GPU to isolate the CPU cooler's noise output.

Test System:

• Processor: Intel Core i5 3570K.
• Motherboard: Asus P8Z77-V.
• Memory: 8GB DDR3 1333MHz.
• Case: NZXT Phantom.
• Cooling Fans: 1x 120mm 1900 RPM Scythe Kaze Jyuni (front intake), 1x 120mm NZXT (side intake), 1x 120mm NZXT (rear exhaust), 1x 200mm NZXT (roof exhaust)
• Graphics card: On-board.
• Power supply: 1000W Seasonic Platinum-1000.
• Storage drives: 128GB Kingston V100 (OS), 1TB Samsung F3, 300GB Western Digital Caviar.
• Thermal Paste: Supplied Noctua NT-H1 thermal compound.

Software:

• CPUID HWMonitor.
• Core Temp (additional certification).
• Prime95.
• Windows 7 Professional 64-bit.

We compared the Noctua NH-L9i CPU cooler to the reference Intel cooler as supplied with our Core i5 3570K CPU. This comparison will give users an idea of the performance differentials that an upgrade may bring.

Our graphs show actual temperatures of the CPU, not delta temperatures.

Ambient temperature was maintained at 19°C.

At stock CPU frequencies, the Noctua NH-L9i manages to offer a performance boost of more than 6% over Intel's reference CPU cooler.

As the thermal load increases and both of these moderately-sized coolers' heatsinks begin to saturate, the lead that Noctua's NH-L9i obtained in the stock CPU frequency test is reduced. Perfectly usable temperatures are offered by both coolers, but it's the NH-L9i that wins this battle with a 3°C, or 3.5%, performance lead.

We measured the noise output of our entire system from a distance of 1m while the CPU cooler's fan(s) operate at 100% (indicating the maximum noise output).

Lower noise levels can be achieved by utilising the Noctua NH-L9i CPU cooler's 4-pin PWM operated fan with a dynamic profile, or by making use of the supplied Low-Noise Adapter (L.N.A.).

With a fan speed of 2500 RPM, the NH-L9i can't compete with Intel's lower-speed cooler. 40.9 dbA isn't a noise level that can be considered as irritating or obtrusive, but when coupled with other quiet components, the NF-A9x14 will be audible to nearby listeners.

The Noctua NH-L9i is a well-designed, low-profile CPU cooler that is able to offer a noticeable performance boost over the cooling capabilities of Intel's supplied heatsink.

Managing to outperform the Intel Core i5 3570K stock CPU cooler with more diminutive dimensions, Noctua's engineering team has designed an efficient heatsink for the NH-L9i. When coupled with the 92mm NF-A9x14 PWM fan, the NH-L9i is able to offer performance that is very respectable, when taking its size into account.

Acoustic levels aren't the strongest aspect of the Noctua NH-L9i CPU cooler – the 2,500 RPM fan operating at full speed is louder than the Intel reference heatsink. A total noise output of 40.9 dbA isn't intrusively loud, although it can be noticed easily when one's system is situated in a quiet room.

If 40.9 dbA is more noise output than you are happy to put up with, simply utilise the PWM fan's dynamic speed control or make good use of Noctua's supplied low-noise adapter that limits fan speed to a maximum of 1,800 RPM.

Installation was a fast and generally straightforward procedure. Holding the cooler in place on the motherboard's front side while fastening it from the back had us urging for an extra hand. One solution is to rest the cooler on a flat surface, although this method can help to promote movement which causes trails of thermal paste to be left over one's motherboard.

One of the Noctua NH-L9i CPU cooler's main issues is its lack of compatibility. Users wanting to carry the cooler over to a different, non-LGA 1155/1156, platform can't use the NH-L9i. Both the Intel, L9i, and AMD, L9a, variants offer support for their individual platform, only.

While both the Intel and AMD versions have their subtle differences, consumers are unlikely to feel happy about being forced into another purchase, should they choose to change platform. The slight performance drop, in the case of the larger NH-L9a, is a worthy compromise for added compatibility.

Priced at £31.99 from Amazon, the Noctua NH-L9i targets mini-ITX and small form factor users, to who complying with space constraints is generally more important than all-out cooling performance. For users that desire a low-profile CPU cooler that offers a noticeable performance improvement and size reduction over Intel's LGA 1155 stock heatsink, the Noctua NH-L9i is a worthwhile purchase.

Pros:

• Very small size.
• Unlikely to cause clearance issues with RAM, VRM heatsinks and motherboard components.
• 6 year warranty.
• Low-noise adapter supplied and PWM fan.
• Can handle high overclocks for a cooler of its size.

Cons:

• Limited compatibility – not cross-platform.
• Fan isn't particularly quiet at full speed.

KitGuru says: A well-designed CPU cooler that eliminates the worry about space constraints and component clearance.

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