Introduction

The Noctua NH-L9i is a low-profile CPU cooler that is only 1.46” (37 mm) tall and uses a 92 mm PWM fan. Let’s test it!

The NH-L9i comes in a small cardboard box, as seen in Figure 1.

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Figure 1: Package

Figure 2 shows the contents of the box: the cooler itself, a tube of thermal compound, manual, a power adapter, a case badge, and four screws. The accessories come nicely fitted in a foam layer.

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Figure 2: Accessories

Figure 3 displays the Noctua NH-L9i.

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Figure 3: The Noctua NH-L9i

This cooler is discussed in detail in the following pages.

The Noctua NH-L9i

Figure 4 illustrates the front of the cooler, where you can see how thin (0.9” or 23 mm) the heatsink is, and the fan (0.55” or 14 mm). You can also see the tips of the two heatpipes.

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Figure 4: Front view

Figure 5 reveals the rear of the cooler.

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Figure 5: Rear view

In Figure 6, you can see the side of the cooler.

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Figure 6: Side view

Figure 7 shows the top of the cooler, completely covered by the 92 mm fan.

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Figure 7: Top view

The Noctua NH-L9i (Cont’d)

Figure 8 illustrates the bottom of the cooler. The nickel-plated copper base is very well polished.

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Figure 8: Bottom view

Figure 9 reveals the heatsink with the fan removed.

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Figure 9: Heatsink

The 92 mm PWM fan that comes with the NH-L9i is shown in Figure 10. The cooler is also compatible with thicker (1” or 25 mm) 92 mm fans.

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Figure 10: Fan

Installation

The installation of the Noctua NH-L9i is very simple. Just put the cooler over the CPU, insert and screw the four screws from the solder side of the motherboard, as shown in Figure 11.

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Figure 11: Screws on the solder side

Figure 12 shows the NH-L9i installed in our computer.

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Figure 12: Cooler installed

How We Tested

We tested the cooler with a Core i5-2500K CPU (quad-core, 3.3 GHz), which is a socket LGA1155 processor with a 95 W TDP (Thermal Design Power). In order to get higher thermal dissipation, we overclocked it to 4.0 GHz (100 MHz base clock and x40 multiplier), with 1.3 V core voltage (Vcore). This CPU was able to reach 4.8 GHz with its default core voltage, but at this setting, the processor enters thermal throttling when using mainstream coolers, reducing the clock and thus the thermal dissipation. This could interfere with the temperature readings, so we chose to maintain a moderate overclocking.

We measured noise and temperature with the CPU under full load. In order to get 100% CPU usage in all cores, we ran Prime 95 25.11 with the “In-place Large FFTs” option. (In this version, the software uses all available threads.)

We compared the tested cooler to other coolers we already tested, and to the stock cooler that comes with the Core i5-2500K CPU. Note that the results cannot be compared to measures taken on a different hardware configuration, so we retested some “old” coolers with this new methodology. This means you can find different values in older reviews than the values you will read on the next page. Every cooler was tested with the thermal compound that comes with it.

Room temperature measurements were taken with a digital thermometer. The core temperature was read with the SpeedFan program (available from the CPU thermal sensors), using an arithmetic average of the core temperature readings.

During the tests, the panels of the computer case were closed. The front and rear case fans were spinning at minimum speed in order to simulate the “normal” cooler use on a well-ventilated case. We assume that is the common setup used by a cooling enthusiast or overclocker.

The sound pressure level (SPL) was measured with a digital noise meter, with its sensor placed near the top opening of the case. This measurement is only for comparison purposes, because a precise SPL measurement needs to be made inside an acoustically insulated room with no other noise sources, which is not the case here.

Hardware Configuration

• Processor: Core i5-2500K
• Motherboard: ASUS Maximus IV Extreme-Z
• Memory: 6 GB OCZ (DDR3-1600/PC3-12800), configured at 1,600 MHz and 8-8-8-18 timings
• Hard disk: Seagate Barracuda XT 2 TB
• Video card: Point of View GeForce GTX 460 1 GB
• Video resolution: 1920x1080
• Video monitor: Samsung SyncMaster P2470HN
• Power supply: Seventeam ST-550P-AM
• Case:  Cooler Master HAF 922

Operating System Configuration

• Windows 7 Home Premium 64 bit SP1

Software Used

• Prime95
• SpeedFan

Error Margin

We adopted a 2°C error margin, meaning temperature differences below 2°C are considered irrelevant.

Our Tests

The table below presents the results of our measurements. We repeated the same test on all coolers listed below. Each measurement was taken with the CPU at full load. In the models with a fan supporting PWM, the motherboard controlled the fan speed according to core load and temperature. On coolers with an integrated fan controller, the fan was set at the full speed.

Cooler	Room Temp.	Noise	Speed	Core Temp.	Temp. Diff.
Cooler Master Hyper TX3	18 °C	50 dBA	2850 rpm	69 °C	51 °C
Corsair A70	23 °C	51 dBA	2000 rpm	66 °C	43 °C
Corsair H100	26 °C	62 dBA	2000 rpm	64 °C	38 °C
EVGA Superclock	26 °C	57 dBA	2550 rpm	67 °C	41 °C
NZXT HAVIK 140	20 °C	46 dBA	1250 rpm	65 °C	45 °C
Thermalright True Spirit 120	26 °C	42 dBA	1500 rpm	82 °C	56 °C
Zalman CNPS12X	26 °C	43 dBA	1200 rpm	71 °C	45 °C
Zalman CNPS9900 Max	20 °C	51 dBA	1700 rpm	62 °C	42 °C
Titan Fenrir Siberia Edition	22 °C	50 dBA	2400 rpm	65 °C	43 °C
SilenX EFZ-120HA5	18 °C	44 dBA	1500 rpm	70 °C	52 °C
Noctua NH-L12	20 °C	44 dBA	1450 rpm	70 °C	50 °C
Zalman CNPS8900 Extreme	21 °C	53 dBA	2550 rpm	71 °C	50 °C
Gamer Storm Assassin	15 °C	48 dBA	1450 rpm	58 °C	43 °C
Deepcool Gammaxx 400	15 °C	44 dBA	1500 rpm	60 °C	45 °C
Cooler Master TPC 812	23 °C	51 dBA	2350 rpm	66 °C	43 °C
Deepcool Gammaxx 300	18 °C	43 dBA	1650 rpm	74 °C	56 °C
Intel stock cooler	18 °C	41 dBA	2000 rpm	97 °C	79 °C
Xigmatek Praeton	19 °C	52 dBA	2900 rpm	83 °C	64 °C
Noctua NH-U12P SE2	18 °C	42 dBA	1300 rpm	69 °C	51 °C
Deepcool Frostwin	24 °C	46 dBA	1650 rpm	78 °C	54 °C
Thermaltake Frio Advanced	13 °C	56 dBA	2000 rpm	62 °C	49 °C
Xigmatek Dark Knight Night Hawk Edition	9 °C	48 dBA	2100 rpm	53 °C	44 °C
Thermaltake Frio Extreme	21 °C	53 dBA	1750 rpm	59 °C	38 °C
Noctua NH-U9B SE2	12 °C	44 dBA	1700 rpm	64 °C	52 °C
Thermaltake WATER2.0 Pro	15 °C	54 dBA	2000 rpm	52 °C	37 °C
Deepcool Fiend Shark	18 °C	45 dBA	1500 rpm	74 °C	56 °C
Arctic Freezer i30	13 °C	42 dBA	1350 rpm	63 °C	50 °C
Spire TME III	8 °C	46 dBA	1700 rpm	70 °C	62 °C
Thermaltake WATER2.0 Performer	11 °C	54 dBA	2000 rpm	49 °C	38 °C
Arctic Alpine 11 PLUS	11 °C	45 dBA	2000 rpm	82 °C	71 °C
be quiet! Dark Rock 2	10 °C	41 dBA	1300 rpm	58 °C	48 °C
Phanteks PH-TC14CS	16 °C	47 dBA	1300 rpm	58 °C	42 °C
Phanteks PH-TC14PE	16 °C	48 dBA	1300 rpm	57 °C	41 °C
SilverStone HE01 (Q)	19 °C	44 dBA	1150 rpm	63 °C	44 °C
SilverStone HE01 (P)	20 °C	57 dBA	2050 rpm	62 °C	42 °C
Thermaltake WATER2.0 Extreme (S)	17 °C	44 dBA	1250 rpm	52 °C	35 °C
Thermaltake WATER2.0 Extreme (E)	17 °C	53 dBA	1900 rpm	50 °C	33 °C
Deepcool Neptwin	11 °C	46 dBA	1500 rpm	56 °C	45 °C
SilverStone HE02	19 °C	49 dBA	2000 rpm	64 °C	45 °C
Zalman CNPS9900DF	23 °C	45 dBA	1400 rpm	68 °C	45 °C
Deepcool ICE BLADE PRO V2.0	22 °C	43 dBA	1500 rpm	67 °C	45 °C
Phanteks PH-TC90LS	24 °C	47 dBA	2600 rpm	95 °C	71 °C
Rosewill AIOLOS	20 °C	40 dBA	1600 rpm	94 °C	74 °C
Corsair H60	20 °C	49 dBA	2000 rpm	64 °C	44 °C
Zalman LQ310	27 °C	51 dBA	2050 rpm	65 °C	38 °C
Noctua NH-L9i	24 °C	44 dBA	2500 rpm	95 °C	71 °C

In the graph below, you can see how many degrees Celsius hotter the CPU core is than the air outside the case. The lower this difference, the better is the performance of the cooler.

In the graph below, you can see how many decibels of noise each cooler makes.

Main Specifications

The main specifications for the Noctua NH-L9i CPU cooler include:

• Application: Sockets LGA1155 and LGA1156
• Dimensions: 3.7 x 3.7 x 1.5 inches (95 x 95 x 37 mm) (W x L x H)
• Fins: Aluminum
• Base: Nickel-plated copper
• Heat-pipes: Two copper heatpipes
• Fan: 92 mm
• Nominal fan speed: 2,500 rpm
• Fan air flow: 33.84 cfm
• Power consumption: 2.52 W
• Nominal noise level: 23.6 dBA
• Weight: 14.82 oz (420 g)
• More information: http://www.noctua.at/
• Average Price in the U.S.*: USD 48.00

* Researched at Newegg.com on the day we published this review.

Conclusions

The Noctua NH-L9i is a very well-made, low-profile CPU cooler, with the same construction quality we are accustomed to seeing in other coolers from this manufacturer.

However, there is no point in comparing the cooling performance of such a low-profile cooler to the high-end tower coolers. Therefore, we must pay attention to the data comparing the portrayed cooler to the stock cooler and other low-profile models.

The NH-L9i is shorter than the Xigmatek Praeton, the Phanteks PH-TC90LS, and the stock cooler. It performed better than the stock cooler, had a performance equivalent to the PH-TC90LS’s, but presented worse performance than the Praeton. It was, however, quieter than those retail coolers, being almost as silent as the stock cooler.

So, if you are building a PC (or an HTPC) in an SFF case and looking for a really low-profile and quiet cooler with better performance than the stock cooler, the Noctua NH-L9i is a product to consider.