[nextpage title=”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.

Noctua NH-L9iFigure 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.

Noctua NH-L9iFigure 2: Accessories

Figure 3 displays the Noctua NH-L9i.

Noctua NH-L9iFigure 3: The Noctua NH-L9i

This cooler is discussed in detail in the following pages.

[nextpage title=”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.

Noctua NH-L9iFigure 4: Front view

Figure 5 reveals the rear of the cooler.

Noctua NH-L9iFigure 5: Rear view

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

Noctua NH-L9iFigure 6: Side view

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

Noctua NH-L9iFigure 7: Top view

[nextpage title=”The Noctua NH-L9i (Cont’d)”]

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

Noctua NH-L9iFigure 8: Bottom view

Figure 9 reveals the heatsink with the fan removed.

Noctua NH-L9iFigure 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.

Noctua NH-L9iFigure 10: Fan

[nextpage title=”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.

Noctua NH-L9iFigure 11: Screws on the solder side

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

Noctua NH-L9iFigure 12: Cooler installed

[nextpage title=”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

Operating System Configuration

  • Windows 7 Home Premium 64 bit SP1

Software Used

Error Margin

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

[nextpage title=”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 < font size="1">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.

Noctua NH-L9i

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

Noctua NH-L9i

[nextpage title=”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: https://www.noctua.at/
  • Average Price in the U.S.*: USD 48.00

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

[nextpage title=”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.