The NZXT Kraken X40 Compact Liquid Cooler Review (Part 3)

7/2/2013 11:19:51 AM


Cooling performance

As you can see from the chart, the NZXT Kraken X40 is not like most of the compact liquid coolers that we have tested before. It operates in such a good way even in its default configuration with one 140 mm fan. The larger heat-sink and high-performance pump is comparable with the Phanteks PH-TC14PE as well as the super-highly efficient Corsair H100i. It turns out to be even better than its competitors when its fans works at the speed of 1870 RPM, defeating the air super-cooler by 3°C in favor of the maximum CPU’s temperature. At the level of 1,200 and 1,000 RPM, the Kraken X40 is also quite efficient, fairly competing with the PH-TC14PE Phanteks and it can easily beat Corsair H100i when both of this device’s fans work at the speed of 1,200 RPM or lower. However, when we reduce the speed of the Kraken’s fan down to 800 RPM, we record a rise of 5°C in CPU’s temperature, so the air super-cooler seems to be better (at its 750 RPM). The Kraken X40 still wins the battle with Corsair H100i at its minimum speed of the fan, though.

Chart for comparing the results

Chart for comparing the results

After we install an additional 140 mm fan on its Kraken X40’s heatsink platform, we receive such an amazing result. There is no rival that can be its competitor in this case, especially at the level of 800 RPM when the secondary fan helps reducing the temperature by 7°C. Note that Corsair can also deliver the same 71°C only at 1,600 RPM, but still it is an impressive result.

Then we check the NZXT Kraken X40 with our CPU which has been overclocked to the frequency of 4.5 GHz at the voltage of 1.435V.

The chart for comparing results

The chart for comparing results

With the default configuration and one fan rotating at the speed of 1000 and 800 RPM, the Kraken X40 cannot cope with the overclocked CPU. The result is not better for Corsair H100i Extreme Performance at 800 RPM. However, the overall picture is the same. It seem that the standard Kraken X40 is somehow better than the VN-TC14PE Phanteks and it can be comparable to the Corsair H100i. The performance of Kraken X40 is improved significantly after we install an additional 140 mm fan, which makes it much superior to the Corsair H100i, the best liquid cooler now, in the speed range of 800 and 1,200 RPM, although its dimension is smaller and its price is lower. It is no doubt that the 140 mm radiator and fans are real advantages.

We tried to test the Kraken X40 at the highest frequency of CPU (4,625 GHz at 1.49 V) but that is such a waste even after we install the second fans on it. All that we receive is an error announcement in the end.

The testing process

The testing process

Therefore, we finish our tests and start to measure the noise level.


First of all, there is something that we wish to mention about the pump. It turns out that the pump works really quietly, compared to the background noise in our quiet testing space. By our method, its noise is about 34.2 dBA. It is comparable to a high-quality 120mm fan whose rotation speed is between 900 and 950 RPM. The operation of the pump cannot be accompanied by any undesired sound from the electric motor or anything. The humble picture just make us worried sometimes due to the air bubbles occasionally going through the pipes and radiator. Therefore, if we stand in this point of view, the pump does a really good job. Let’s check out the fan, which is the main noise source inside the Kraken X40 system.

We measure the noise level of the fan throughout its entire speed range in the way that we have mentioned in the previous part, and here are the results

The chart showing noise level

The chart showing noise level

At the low speed of fans (up to 1050 RPM), the results delivered by these three coolers are not really different, except for the Phanteks PH-TC14E in its default configuration with 2 fans. The performance of the NZXT Kraken X40 is still very smooth until its speed reaches 930 RPM. Its fans are quiet at 800-850 RPM, which is the minimum speed that we tested. However, when the speed exceeds 1050 ROM, the large 140mm fan from the NZXT seems to be noisier than two Corsair fans from the H100i cooler. The difference becomes larger at the same speed, although the Corsair cooler makes louder noise at its maximum speed. It is notable that the NZXT seems to be more acceptable compared to the Corsair when the fan speed is low.


Moreover, when equipped with two 140 mm fans, the Kraken X40 manages to fight a fair battle with the more expensive Corsair H100i Extreme Performance. That is not to mention the air cooling system. Therefore, this product seems to go on the right way in terms of performance.

The NZXT Kraken X40 just supports cases which have enough space for a 140mm fan. Although the compatibility list has been extended to 50 models and will be continuously expanded, such cases are less common than the more popular ones with the 120mm fans. On the other hand, the Kraken X40 supports as many platforms as possible, including CPUs of Intel and AMD. The installation process is so simple, with the solid installation structure, and the long pipes that allow you to put the radiator anywhere in the case. It just cost $99, higher than the price of liquid cooling system with 120 mm fans series, but not any high compared to the senior solution products or the Corsair H100i.

Specifications and price


·         Dimensions: 138.4 x 172.5 x 27 mm

·         Effective body width: 16mm

·         Fitting diameter: 10mm

·         Material: aluminum


·         Dimensions: Ø72x32

·         Performance: N/A

·         Rotor rotation speed: 2900 (±150) RPM

·         Bearing: ceramic

·         Nominal voltage: 12V

·         Power consumption: 7.5W


·         Fans: 1

·         Model: NZXT FX-140KRX-PWM

·         Dimension: 140 x 140 x 25mm

·         Bearings: 800 – 2000, PWM

·         Airflow: 54-98.3 CFM

·         Noise: 21 – 37

·         Static pressure: 0.8 – 2.2 mmH2O

·         Nominal voltage: 12 V

·         Max. power consumption: 7.08 W

·         Fan MTBF: 35,000 hours

Water block

·         Model: no data

·         Material and structure: copper,  micro-channel structure

·         Platform compatibility: Intel LGA 1155/1156/1366/2011 AMD Socket AM2(+)/AM3(+)/FM1(2)


·         Tubing length: 400 mm

·         External tubing diameter: 10mm

·         Coolant: non-toxic, anti-corrosion (propylene glycol)

·         Warranty: 2 years

Price: $99


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