NZXT Kraken X40 & X60 Sealed Liquid CPU Cooler Review

Pardon the cliche', but it must be done. NZXT RELEASES THE KRAKEN! Now since that is out of the way, we take a long [H]ard look at NZXT's new line of Kraken branded sealed system water coolers for your CPU. This type of cooler is quickly becoming the norm for many enthusiasts looking for a quick and easy cooling solution.


Up until now Corsair has been given the lion’s share of the attention when it comes to closed loop water cooling and with good reason. The Corsair H90 and H110 CPU water coolers have created a lot of excitement given the performance and low noise characteristics and the H80i and H100i units for blending software control with top of the line performance. Corsair however is not the only game in town and worth mentioning is that Antec is getting back into the "Kuhler" game as well with new products.

NZXT is here to take a bite out of Corsair’s pie with its Kraken line of water coolers consisting of the Kraken X40 and Kraken X60. There are a lot of similarities between the Kraken coolers and Corsair’s H series coolers as these are both produced by Asetek. These both use 140mm fans and larger radiators but NZXT tells us that their Kraken coolers are the only ones to use Asetek’s new pump and cold plate design which should give NZXT the edge; a claim we will most certainly put to the test. So while identical from an external view, new internals will hopefully give us something to talk about.

Article Image

System Setup

Today's review utilizes our third generation [H]ard platform. The test bed consists of the ASUS P8Z77-V motherboard, eight gigabytes of Corsair 1600 MHz DDR3 RAM and the Intel Core i7 3770K. This will be updated to the Haswell Core i7-4770K platform soon as we cull through to find some of the hottest CPUs.

Article Image

Test Methods


The biggest change you will notice is the removal of hardware testing. In recent years, Intel has shifted their methods of testing to software based and so we find it acceptable to do the same.

Article Image Article Image


For the first time, we have an integrated GPU in our processor which alleviates the need for a discrete one. With the removal of a discrete GPU comes the advantage of not having an additional variable to account for.

The iGPU will not create any anomalies in our testing as long as we practice consistent testing methods.


Corsair was kind enough to provide us with their Carbide series chassis. It provides excellent airflow and interior space and is a good reflection on current case design.

Thermal Paste

Noctua's NT-H1 thermal paste was selected as the paste of choice for a few key reasons. The thermal paste has been shown to provide excellent thermal conductivity allowing the heat sinks to better do their job. There is no observed curing time. That is, performance does not get any better over time. Any curing time could have introduced variables into the equation causing at best dubious results and at worst unreliable ones.


Ambient temperature will be kept at 25C for the duration of the tests and measured with a MicroTemp EXP non-contact infrared thermometer and cross referenced with the Sperry Digital 4 Point thermometer. Any variance greater then 0.2C will halt the testing until temperatures return within spec for fifteen minutes.


Idle temperatures will be recorded after a twenty-five minute period of inactivity. Any fluctuation during the last sixty seconds will reset the timer for an additional five minutes.


Load temperatures will be recorded after a twenty-five minute period of 100% load. To obtain this load we will be using Prime95 v27.7 set to in-place large FFTs mode. In this way we can place the maximum amount of heat into the CPU. Any fluctuation during the last sixty seconds will reset the timer for an additional five minutes.


Sound levels will be measured with a Reliability Direct AR824 sound meter from a distance of four feet away. With everything turned off and the room completely silent the meter registered a sound level of 38dB(A). This is a very quiet room where a simple pin drop could be heard. All sound measurements are recorded in the very late evening to further reduce any ambient noise.