NZXT Kraken X42 CPU Cooler Review 18


NZXT are well known and well regarded for their quality, innovation and styling so there’s not much that I can say about the company that will be new or surprising. They have their finger on the pulse of cases, cooling, power and lighting with their Hue+ which Gavin raved about in his review. It’s cooling that we will consider today as we take a look at the latest incarnation of their very successful Kraken range. I have the Kraken X42, which is an All-In-One or AIO water cooler with a 140mm radiator, extended tubing to reach any vent on your case you wish to use and RGB lighting with two separately controlled zones to really give it some individuality. In fact, if you have their Hue+ system you can incorporate the Kraken lighting in with the rest of your lighting design.

With this being their smallest radiator in the Kraken X*2 series we can’t expect insane cooling and off-the-charts success but NZXT has a reputation to protect and that’s something that hangs in the balance with every new design or product refresh. Will their rep be enhanced with the X42 or will it be in tatters? Time will tell as we get to the testing, but first the features and specifications of the Kraken X42.


  • New performance engineered pump
  • Individually addressable RGB and infinite mirror design
  • CAM Powered for complete software control
  • Includes Aer P radiator-optimized fan
  • Advanced lighting modes for a fully dynamic lighting experience
  • Reinforced, extended tubing for increased durability
  • Industry-leading 6-year warranty


Dimensions Radiator: 175 x 143 x 30mm
Pump: 80 x 80 x 52.9mm
Material Aluminum, copper, plastic, ultra-low evaporation rubber, nylon sleeving
Weight 890g
CPU Socket Support Intel Socket 1151, 1150, 1155, 1156, 1366, 2011, 2011-3
AMD Socket FM2+, FM2, FM1, AM3+, AM3, AM2+, AM2
Control Modes Fan: Silent / Performance / Custom / Manual
Pump: Silent / Performance / Custom / Manual
Control Method Software with CAM
LED Modes Preset Modes: Fixed, Breathing, Fading, Marquee, Covering Marquee, Pulse, Spectrum Wave, Alternating, Tai Chi, Water Cooler, Loading
Reactive Modes: Smart and Audio
Pump Speed 1,000~2,800 +/- 300RPM
Fan Model Aer P140
Number of Fans 1
Fan Speed 500~1,800 +/- 300RPM
Fan Noise Level 21-38dBA
Warranty 6 years
Model Number RL-KRX42-01
UPC 815671012852
EAN 5060301693184


The overall styling of the Kraken X42 packaging is fairly simple. The front of the box simply shows an image of the AIO cooler with the fan fitted on a white background along with the product name and description being a 140mm liquid cooler. Indeed, the only mention of NZXT is on the image itself, aside from that no other logo is shown.


The back retains the white background and includes plenty of information about the AIO cooler, the new fans, extended tubing and RGB supported by CAM software.


The side contrasts having a purple background listing the facts and figures for the Kraken X42.


The last side lists the features of the cooler in many languages again on a purple background.


Breaking into the packaging we finally see the contents and it’s more or less the usual fair that you might expect, the AIO cooler, fan, fittings and plastic backplate along with two cables. One cable is for a USB connection and the other comprises many different sockets for SATA power, up to two fans and CPU fan socket for PWM control of the pump and fans.


nzxt-kraken-x42-aio-accessories-box-front AEO P140

Along with the Kraken X42, NZXT sent another package containing a fan trim that can be swapped out to match your X42 to your rig – in case the RGB options weren’t enough. It’s contained in a simple white box with just a line drawing of the trim itself and the product name that it fits too.


The rear of the box shows another line drawing, this time with instructions for the removal of the existing trim along with the specifications.


We were sent the blue variant and there’s actually two in the pack so if you choose to push-pull your radiator or add a second fan in your rig you can accessorise both.


Replacing the existing trim is as simple as it looks in the description. Simply use a very small screwdriver or anything else that you can poke through the gap to release the corners of the trim and pop it out then snap the new one into place and you’re done.

Let’s move on and take a close-up look at the Kraken X42 in all its glory.

Closer Look


The fan NZXT has chosen for the Kraken X42 is their new AER P140 which is a seven-bladed affair which as we have already seen comes with the ability to swap out the rim for a colour of your choosing, at least within their small current selection.


The PWM fan has a Fluid Dynamic bearing and is capable of running at around 500~1800 RPM without the earsplitting noise that usually accompanies a full speed fan. In fact, it’s fairly quiet while on an open testbench even though it can push almost 100 CFM through a radiator when at full pace.


The PWM cable is wrapped in a woven sleeve of reasonable quality, which is more than can be said for other cables on the X42 unfortunately.


The AIO loop itself is outwardly similar to any other Asetec liquid cooler. The pump sits atop the cold plate, it’s connected to the radiator by flexible tubing and in this case, the radiator is aluminium and accommodates a 140mm fan while also acting as the liquid reservoir.  Being an Asetec design we are assured of quality and compatibility which NZXT have taken and tweaked to their satisfaction.


The first of those customisations that NZXT have applied is to the flexible hose. It’s very nicely braided and extended to a length of 400mm to allow the radiator to easily fit the front of any case as well as the usual areas on the roof or rear.


The pump is made of copper and plastic and runs around 1000~2800 RPM. NZXT have already prepared the copper cold plate with Thermal Interface Material (TIM) although for the sake of continuity as well as to remove a variable we run our thermal tests using Noctua’s NT-H1.


Although made of plastic, the design of the pump housing includes a rather nice brushed effect that runs around the circumference of the top half of the housing and offers a nice contrast to the ‘bare’ finish on the lower section.


The party piece of the Kraken X42, as well as others in the range, is the top face of the housing that contains an infinity mirror along with the software controlled RGB lighting which uses CAM.

Test Setup

CPU: Intel Core i7 4770k
Motherboard: MSI Z97I Gaming AC
Memory: 16GB (2x8GB) Team Group 2666MHz
Cooler:  NZXT Kraken x42
Thermal Paste: Noctua NT-H1
Storage: Sandisk Ultra II 240GB


Installation and testing were carried out on a test bench rather than inside a conventional case. While this has the benefit of being easier to physically install as there is not as much stretching as well as easier access to motherboard jumpers and sockets, it has the disadvantage of not having any reduction in sound so what I hear may be more exaggerated than if it were in a case.

Software and RGB

When testing the software we go through the expected use cases to see firstly if the software performs as expected, then we further experiment to try to find any unexpected events and decide if these are beneficial such as a feature not described in the manual or unwanted such as a malfunction. These tests are brief when compared to a full software test that would be run by the provider prior to release or performed at BETA stage by volunteers.

Thermal performance

Thermal performance is judged on four factors overall; the idle temperature at stock and overclocked speeds, as well as the loaded temperatures at stock and loaded speeds. During the testing, whether that be the idle or loaded testing, the system is either at idle or full load for a duration of five minutes before any readings is taken. The average temperature across all four cores is then noted down and used as the results. All room temperatures are recorded beforehand as well as during the test to ensure that the delta temperature is as accurate as possible.


Physically installing the Kraken X42 was a straightforward process that is found on many Asetec based coolers. First, you select the motherboard series you are using and move the sliding nuts appropriately and then sandwich the motherboard between the backplate and four upright posts. Then the pump section is placed over the cooler (replacing the TIM if necessary) and secure it in place with four nuts that can be tightened by hand although there is a cross-head screwdriver slot in each nut to help you.

NZXT have helpfully provided a video showing the process which may be handy for first-timers and those who may not be as confident with written descriptions.

The process was completed smoothly and quickly without any unexpected drama. Whether that’s down to excellent engineering or the sheer number of this type of cooler I’ve installed I’ll let you decide but the facts remain that this is the first opportunity for the process to fail due to poor quality fittings and it didn’t; the sliding nuts remained at their specified placement while fitting the backplate, the posts screwed in easily by hand and fitting the pump unit with the bolts was a cinch. I think NZXT missed an opportunity when it came to the wiring loom that comes with the Kraken. It is long enough to reach all the necessary areas of the motherboard as well as the Aer P140’s lead but sadly it is not covered at all. Considering the price of the unit (I couldn’t find it any cheaper than £80) I don’t think that would have been too much to ask for.

Software and RGB

We have talked about the CAM software in detail in the past in our reviews for GRID+ as well as HUE+ and the premise is the same here. Installation of the software is via a simple download which installs the Asetec drivers as well as CAM, however, there was a problem getting the program to recognise that the Kraken X42 was installed.

The problem arises from one of the commands in an installation window – you are asked to only install the components that you have physically installed and so I selected the Kraken tick box and this installed the drivers. That box however refers to a previous version of Kraken and the drivers are not compatible with the X42 which left me scratching my head. In fact, the X42 is plug and play and only needs the ASETEC drivers so when installing CAM you should in fact leave the Kraken tickbox blank. If you know about this issue (and it is a known issue that NZXT are working on) then it’s simple to avoid and installation will continue without delay.

NZXT Cam Install Screenshot

Finally, with working software, I was able to use the RGB functionality and it was a very entertaining experience being mesmerised by the different patterns that are available from a simple ring of RGB LEDs. Gavin took a closer look at the capability of the CAM software and shows us its range in this video.

What isn’t mentioned in the video is the full capability of the CAM software and I’m sure that even after reading this an experienced user will turn around and say we missed something ‘obvious’. Firstly, the video shows the range of options when you select both the logo and the ring, but if you select just the ring you will be astounded as the list of options is expanded. indeed, you can go for one effect for the logo and a totally different one for the ring if you so choose. The other important capability is that you can set CAM to show problems related to overheating, by having one colour for ‘cool’ and another for hot components.

If you know of other important features of CAM that I’ve missed then please let me know in the comments as sadly there’s no guidebook for the software and with so many options available I think that’s something that could, and should, be included.

Thermal Performance


Starting with the temperature at stock speed and our Intel processor idling, we have a fair performance from the X42. It sits happily in the top half of the chart nestled among a number of other watercoolers.


Pushing the processor to its full output changes things for the Kraken X42 however. The delta temperature of 30.5°C is a poor showing from an AIO with the combined pedigree of Asetec and NZXT. The result is not bad – the chip is in no danger and it is half the temperature of a stock cooler – but other coolers are better at this specification and so the result identifies as being poor by comparison.


Changing things up a step and overclocking the processor to 4500 MHz and we again look at the idle temp. Rather confusingly the Kraken X42 outperforms almost all other coolers on this test and finds itself in the Top 5.


Our final test sees how the NZXT cooler performs when set against our overclocked cooler running flat-out. This time we have a much better showing. It is if course hotter than the stock temperature but it was able to keep the processor cooler than a lot more of its competitors finishing at number 12 in the chart.

Normally we would expect to see a cooler that is good or great when overclocking the CPU to also be good or great at stock speeds but of course, this was not the case here. The only logical explanation is that while other coolers were able to cope really well with a stock processor, they may have been near the limit of their cooling potential and so performed far worse when the processor was overclocked. The NZXT Kraken X42 not unique in this position, both the Cooler Master Hyper 212X and Hyper TX3i also appear fairly low in the stock, full load chart and much higher than first expected when overclocking.


And so we conclude our time with the NZXT Kraken X42 and what a wild ride it’s been, full of highs and lows. But if this has all been a little TL: DR for you then I’ll try to break it down into the Reader’s Digest version.

The NZXT Kraken X42 comes across as a premium product with a price tag, I really do feel that regardless of the technology incorporated in it that £120 is way too steep for a 140mm single fan AIO. Yet the look and feel of the Kraken might make you question that statement. After all, it really does look awesome with the brushed finish and the RGB effects available that are enhanced by the infinity mirror, but then it’s ruined by a simple wiring loom that could have and I think should have been braided.

The physical installation went without a hitch but when it came to the software I was totally stumped. If I already had Hue+ or even just CAM installed on the testbench then I could have installed the Asetec drivers and the rest would have been plug and play, but I was accidentally installing old Kraken drivers and corrupting the whole process. As I mentioned earlier, the problem is a known issue and I’m sure NZXT will resolve it quickly.


On to another high point though because with CAM and the Kraken seeing eye to eye I had plenty of fun procrastinating as I played with the lighting effects. There’s a lot of time that is wasted when testing coolers as you have to ensure that temperatures are stable etc, and it almost seems that the dual zone RGB effects were designed with time-wasting in mind. Kettle’s boiling? Play with the Kraken. On the phone waiting in a queue? Play with the Kraken. Brain freeze while writing a review? You get the picture. Of course, if your PC is on display then sticking with one colour scheme and effect will accentuate your components rather nicely.

I said in my opening statements that a 140mm AIO was not going to break any records as far as cooling performance goes, but I wasn’t ready for just how mundane the performance was at stock speeds once the processor was pushed. I really thought that with the pedigree of NZXT the Kraken X42 would be at least in the top half of all cooling charts, not nestled among so many air coolers. After all, I wasn’t testing with a PWM profile, I had everything turned up to max… but there we have another problem. You CAN’T have everything turned up to max. If you set the fan curve to 100% you would expect everything to run at 100% but there’s a small section of the curve that stubbornly refuses to shift from its starting point and so the fan and pump were throttling constantly, especially on the idle tests. Add to this the fact that the cooling curve chart doesn’t have any temperature or performance markers at all on it making any custom curve on CAM total guesswork, leaving you with software that just feels half-hearted and a little Beta.

If you come across any problems, the Kraken X42 comes with a pretty amazing 6-year warranty and I would expect the majority of people to consider this a fair lifespan for any computer since the minimum spec climbs quite rapidly for both office software and gaming.

I’ve touched on the price a few times, but I think it needs to be stated clearly – this is a very expensive item. Running at £119.99 at Novatech in the UK at the time of writing and frankly, I can’t justify it when there are so many alternatives that offer similar features and benefits. This is something that fans will want or those who really want to use CAM to fully customise all the components of their system, but anyone wanting a quality cooler on a budget will most likely pass on the Kraken.

I would like to thank NZXT for sending the Kraken X42 for us to review and congratulate them on their entertaining and beautiful implementation of RGB utilising an infinity mirror, but sadly it’s not quite enough to win our Design Award this time.


– Loads of RGB effects available with the CUE+ software
– Good looking with an infinity mirror on the pump
– Interchangeable coloured fan borders available to buy separately
– Quiet pump and fan, even when not enclosed in a case


– Quietness is achieved at the cost of lower performance
– It’s very expensive for an AIO based on a 140mm radiator

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nzxt-kraken-x42-cpu-cooler-reviewNZXT's RGB refresh of the Kraken range is very appealing, but the Kraken X42 fails to deliver on performance and value to win any awards today. That being said, the NZXT Kraken X42 is one of the best-looking coolers on the market and if you want to component match with other NZXT products, you won't be disappointed!


  1. Can you at least put the Kraken scores in a different color so we don’t have to go hunting for it in every chart?

    • Hey Darksword, I think this is an oversight, but don’t worry, I will make sure that he doesn’t do it again!

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