NZXT Kraken X61 CPU Cooler Review

 

We’ve recently been taking a look at some of the most recent AIO (All-In-One) liquid CPU coolers currently available. Ranging from the traditional closed loop, to the expandable and customisable, AIO with the smaller 120mm radiators to the more popular and often more capable 240mm. What we haven’t seen or tested so far on our current Test Rig is an AIO CPU cooler with a larger radiator. Something which should benefit CPU cooling for two big reasons. Firstly a larger radiator means we’ll have a larger surface area with which to dissipate the heat created by an overclocked CPU, which often also means a more substantial overclock without the side effect of polar ice cap melting temperatures. Just as importantly is the larger surface area also allows the use of bigger fans, which often spin at a lower RPM whilst providing the same cooling benefits, but with the added side effect of creating less noise. What we have here today is the latest and largest offering from NZXT in the form of the NZXT Kraken X61. A closed loop AIO liquid CPU cooler, with a 280mm radiator, two 140mm PWM fans and an easy mounting assembly. What makes it slightly different to most is the LED illuminated pump is colour customizable courtesy of the NZXT CAM software suite, but in addition to this the NZXT Kraken X61 is also the first AIO available to the public that features an integrated variable speed pump.

So this means the NZXT Kraken X61 is a great CPU cooler? Let’s find out!

 

 

 

The NZXT Kraken X61 arrived at pcG within a rather clean looking, predominately white box which seemed surprisingly lacking in details. Of course this only helps to draw our attention to the massive image of the Kraken X61 image on the front. Otherwise we are just left with the cooler name, the description of the X61 being ‘The World’s First Variable Speed Liquid Cooler’, the company logo and we are also told the AIO has a staggeringly long 6 year warranty.

Looking over on the back and it would seem the minimalist approach is the order of the day. Once again we have an image of the Kraken X61 along with some pictograms of its highlighted features. In the lower left we have some screenshots for the NZXT CAM software, alongside bullet points for all of the NZXT Kraken X61 key features as follows:

• Our 280mm radiator platform gives 36% more surface area over comparable 240mm coolers.
• High performance variable speed pump and copper coldplate.
• Integrated Hue and digital fan control with CAM compatibility.
• New FX140 V2 PWM fan tuned for performance radiator cooling.
• Large tower support with extended 16″ tubing and premium black sleeved cables for a clean look and improved airflow.
• Completely sealed system backed by an industry leading 6 year warranty.

 

 

On the left and in complete contrast to the front and back with a black and bright red colour scheme, we have the Kraken X61 specifications (see Specifications/Features below).

Whilst looking to the right and in the same colour scheme, we a full CPU socket compatibility list, alongside a performance comparison between the NZXT Kraken X61 and its 280mm radiator, a standard 1″ thick 240mm radiator cooler and a standard 1.5″ thick 240mm cooler (no digs at the competition of course 😉 ).

 

 

Unlike many of the other AIO liquid CPU coolers I’ve seen of late, instead of a flip top box, the NZXT Kraken X61 box is of the more traditional variety. When opened we find the typically familiar egg-box styled cardboard tray holding the X61 and its accessories safely in place. The 280mm radiator is further protected by a white cardboard sleeve, where as the other items are safely tucked away in clear plastic bags.

With the Kraken X61 removed from its packaging , we find the coldplate is also protected by a clear plastic cover. This isn’t just to help prevent any damage or scratches to the base whilst in transit, but also to help keep the pre-applied thermal paste in place.

 

Box Contents

 

 

At the time of review, the NZXT Kraken X61 is available from Amazon for £120.00 or from OverclockersUK for £119.99 and offers an incredible 6 year warranty!

 

Specifications/Features

courtesy of NZXT

 

 

* Additional details available here

 

First Impressions

 

In a rather bizarre twist, the NZXT X61 radiator seems much larger in hand than it really is (ok, perhaps that might just be because most of the AIO recently tested have been of the 240mm variety). As we can see from the side the radiator has been powder coated matte black, with three simple studs holding the side frame on. Towards the pipe end features a stamped code of some sort (10-100-222000), what this is for? I’ve no idea… Surprisingly looking at the difference in depth between the side frame and the radiator fins, there is a considerable difference. Of course this actually is of benefit whilst installing as it helps to prevent damage to the fins and coolant pipes.

Looking at the radiator end, we find that both the inlet and outlet are fixed and feature tubing are made from black rubber, with a total length of 400mm. This means the tubing is plenty long enough for even the largest of cases, whilst being flexible enough to squeeze into the smallest and confined ones.

The radiator itself measure measures in at 140(W) x 280(L) x 27mm(D). As NZXT mention on the packaging (once or twice!), this means the 280mm radiator has 36% more surface area than that of a typical 240mm. The radiator itself may not look hugely exciting, but it is incredibly solid with a thick frame, so it is unlikely to get damaged through installation (or repeat installation either). Of course just like any other radiator featuring aluminium fins, we’ll have to be a little careful not to bend them.

 

 

As we can see from above, the NZXT Kraken X61 pump top is round in shape and oddly without the mounting bracket on, looks a little similar to a cog. The cap itself is matte black and features the NZXT logo with a circular pattern running both through and around. This should look pretty good when installed alone, but when powered on the logo and pattern will illuminate, better yet when used in conjunction with the NZXT CAM software, we can even change the LED colour to suit our Gaming rig colour scheme better. What makes this pump so special isn’t the lighting either, but the fact that through the NZXT Cam software, we can also adjust the pump speed from 2400-3600 (±150) RPM. Something which is very new to the AIO world .

From the side we find the Kraken X61 to be largely featureless until you get to this one very busy area. Here is where we find right angled elbows for the tubing input and outputs, both of which are rotatable to make for an easier installation. Just to the right of these we have three heavy duty braided cables (seems a little extreme, I wonder what these could be for?!).

Looking more closely at the coldplate and you’d be forgiven for mistaking the Kraken X61 for one of the Corsair Hydro range such as the H105. It has the same shape, same copper baseplate with the same finish, it shares the same screws for the same fittings and even shares the same pre-applied thermal paste. This isn’t because NZXT have pinched the design from the popular Corsair line up, but because both share the same OEM, seasoned veterans of the AIO cooling world, the Danish megalith that is Asetek.

 

 

Getting back to the cables poking out of the side of the Kraken X61 pump. These all feature heavy duty nylon braiding and although unlikely to damage or fray very easily, aren’t as flexible as I for one would like. One cable ends in a SATA header to provide power to the fans, another features a USB plug in order for us to be able to control the pump and fan speeds via NZXT CAM, a single three pin power cable to connect to the motherboard and power the pump, then a four way PWM fan splitter cable. The latter of which is very handy for if you decide to use an additional 2x 140mm fans in a push/pull configuration.

Overall the NZXT Kraken X61 presents a rather nice package. Now it’s time to get the Kraken X61 installed into the Test Rig.

 

Hardware Installation

 

Test Rig Setup

Case	Cooler Master HAF XB	Power Supply	Corsair Professional Series AX 760i
Motherboard	ASRock Fatal1ty Z97X Killer	CPU	Intel Core i5-4690K
CPU Cooler	NZXT Kraken X61	RAM	HyperX Savage 2400MHz 8GB Kit
Graphics Card	XFX AMD Radeon R9 290X DD Black Edition	SSD	HyperX FURY 120GB

 

 

In order to install the NZXT Kraken X61 we first need to separate the LGA 1150 fittings out from the AMD and Intel Socket 2011 fittings, along with the few screws for the radiator and fans that we won’t be using. A nice and easy task, not because they are separately bagged, but because there are actually very few fittings anyway. As you can see from the images above, the Kraken X61 uses the familiar and very easy mounting system that most of the Asetek based AIO CPU coolers do. The plastic backplate simply lines up to the back of the ASRock Fatal1ty Z97X Killer, the adjustable slide mounts are then moved to the appropriate positions and slot through the motherboard CPU mounts and then held in place by the dual threaded upright bolts. There is quite a degree of free movement once installed as the backplate doesn’t sit tight against the motherboard, but once the pump is installed will be clamped in place and offer no movement at all.

 

 

With the backplate in place, the protective plastic cover is removed from the X61 pump, the mounting plate is then slotted over the pump and locked in place and the pump ready to install. Normally we’d use a small amount of Arctic Cooling MX-4 to help create a better bond between the i5-4690K and the CPU cooler, but in the case of the Kraken K61 the paste is pre-applied. So the pump assembly simply slots over the uprights and held firmly in place with one hand, whilst each of the four nuts are screwed onto the uprights from corner to corner. It’s a tried and tested formula that is so easy it can be installed within a matter of minutes.

 

 

Next up we have the 280mm radiator and the 140mm FX V2 PWM fans. These can be fitted in a number of ways and NZXT provide enough fan screws for you to do so. If you so wish, you could mount the fans on the inside of the radiator and case in either a push or pull configuration (this is also less fiddly as the fans are attached to the radiator, which is then attached to the case), but in the case of the Cooler Master HAF XB we use for our Test Rigs, I’ve chosen to take advantage of the external fan mounting space just to give a little extra cable management space (and it looks a lot nicer in my opinion too).

 

 

Which just leaves us having to plug in the SATA power, USB, fan and pump cables into their respective places. The installation of the NZXT Kraken K61 is easy, in fact very easy. With a bare system, installation of the cooler alone could be as quick as five minutes! All helped by the nice and simple mounting system and the tough but very flexible rubber tubing.

 

 

Then with a press of a button, a whir of fans, along with a gurgle from the pump and the Test Rig comes to life. As you can see from the images above, the LED pre-set is of a very pale blue colour, which doesn’t look too bad, but whilst not too intrusive will be the first thing I play around with within CAM.

 

 

NZXT CAM (available here) is a hardware monitoring tool offering a plethora of features. The application itself looks very clean aesthetically and easily customizable in case you aren’t a fan of the blue and white. Of course the area we are interested in is the Kraken software. We can do this in one of two ways, either via the main dashboard where we simply select change mode, then save your chosen profile to activate it. We then are given information on the liquid temperature, fan speed, pump RPM and fan RPM (although not in this case apparently…). Alternatively by selecting the Kraken header, we are given the same information and access to profiles, but also gain the ability to set up our own profiles. Just as importantly CAM also allows us to change the pump LED colour, with a choice of 48 basic, or one of 16 custom colours. We also have four different lighting effects to choose from, standard leaves us with one solid colour, alternate switches between your two chosen colours, blinking is simply a slow repetition of on and off, then off which is as described.

 

 

The choice of colour is of a great benefit and will help the NZXT Kraken X61 fit in with any Gaming rig colour scheme and look good whilst doing so. On the whole the LED colour representation is pretty good, until you try to use white (which seems to be a common problem for many manufacturers). The lighting effects are a bit of a throwaway though and not especially pleasant to see, hopefully NZXT will add a breath or spectrum effect to the CAM software at some point in the future.

Now it’s time for some thermal benchmarks!

 

Testing Methodology/Setup

 

* Please note: To ascertain the maximum and minimum noise levels produced by our CPU test coolers. The dB is recorded at a distance of 1 metre from the cooler, with all case fans unplugged to isolate the sound in question.

 

 

Processor speed is set using the OC Tweaker tab of the UEFI, “Disabled” for stock speeds (3.5GHz) and “Turbo 4.0GHz” for the minor overclock tests. It should be noted that changing the OC settings resets the Fan Speeds, so these are checked on the next reboot and reset to “Full Speed” (see below).

 

 

All the fans installed in the system are set to 100% speed using the displayed settings, this is simple with the ASROCK UEFI with the option of “Full Speed” being available for all system fans (bar the Power Fan header).

 

 

Hardware Performance

 

As stated above, to make our performance tests easier to follow and to get the most accurate recordings, all of the following tests have been carried out with case fan set at 100% via the UEFI, then both of the NZXT FX V2 140mm Performance PWM Fans and the Kraken X61 pump were also set at 100%.

 

• Intel Core i5-4690K – 3.5GHz (stock)

 

 

CPU Cooler	Air/Liquid	Fan Speed	Ambient Temperature	Max CPU Temperature (core average)	Delta Temperature	Noise Level
NZXT Kraken X61	Liquid	100%	24.50	40.75	16.25	51dB
Deepcool Gamer Storm Maelstrom 240	Liquid	100%	24.00	43.50	19.50	50dB
Noctua NH-D15	Air	100%	25.00	44.75	19.75	44dB
Fractal Design Kelvin T12	Liquid	100%	25.00	46.00	21.00	40dB
Reeven Okeanos	Air	100%	22.00	43.75	21.75	45dB
SilverStone Tundra TD03-E	Liquid	100%	25.50	49.25	23.75	51dB
Corsair H105	Liquid	100%	23.00	46.75	23.75	60dB
Reeven Justice	Air	100%	21.50	46.50	25.00	39dB
Reeven Hans	Air	100%	26.00	51.50	25.50	34dB
Raijintek Themis Evo	Air	100%	21.50	47.50	26.00	37dB
Noctua NH-U9S	Air	100%	24.00	50.00	26.00	38dB
Scythe Mugen Max	Air	100%	22.00	48.50	26.50	36dB
Reeven Ouranos	Air	100%	22.00	48.50	26.50	43dB
Raijintek Themis	Air	100%	21.50	52.25	30.75	47dB
Cryorig C1	Air	100%	23.00	56.25	33.25	42dB
Noctua NH-D9L	Air	100%	25.00	55.75	30.75	33dB
SilverStone Argon AR06	Air	100%	23.50	79.50	56.00	28dB

* Thermals Explained

 

I’ll admit that I was expecting the NZXT Kraken X61 to be good, owing to its 280mm radiator, but certainly not as good as the recorded results show. With the i5-4690K set at its 3.5GHz stock speed, the Kraken X61 keeps the maximum average CPU core temperature at 40.75C with a Delta of just 16.25C. Its nearest competition being the very cool Maelstrom 240 with a maximum average CPU core temperature of 43.50C and a Delta of 19.50C. Making the NZXT monster cooler by 2.75C (3.25C Delta).

Let’s see how it handles an overclock.

 

• Intel Core i5-4690K – 4.0GHz (OC Tweaker)

 

 

CPU Cooler	Air/Liquid	Fan Speed	Ambient Temperature	Max CPU Temperature (core average)	Delta Temperature	Noise Level
NZXT Kraken X61	Liquid	100%	24.00	48.00	24.00	51dB
Fractal Design Kelvin T12	Liquid	100%	26.50	53.75	27.25	40dB
Deepcool Gamer Storm Maelstrom 240	Liquid	100%	24.50	52.50	28.00	50dB
Reeven Okeanos	Air	100%	23.50	51.75	28.25	45dB
Noctua NH-D15	Air	100%	24.00	52.50	28.50	44dB
Corsair H105	Liquid	100%	23.00	53.50	30.50	60dB
Scythe Mugen Max	Air	100%	22.00	54.75	32.75	36dB
SilverStone Tundra TD03-E	Liquid	100%	26.00	58.75	32.75	51dB
Reeven Justice	Air	100%	22.00	55.25	33.25	39dB
Reeven Hans	Air	100%	25.00	59.25	34.25	34dB
Reeven Ouranos	Air	100%	24.00	58.25	34.25	43dB
Raijintek Themis Evo	Air	100%	21.50	58.00	36.50	37dB
Noctua NH-U9S	Air	100%	23.50	60.25	36.75	38dB
Raijintek Themis	Air	100%	21.00	59.50	38.50	47dB
Noctua NH-D9L	Air	100%	24.50	67.00	42.50	33dB
Cryorig C1	Air	100%	23.00	65.75	42.75	42dB
SilverStone Argon AR06	Air	100%	23.50	92.50	69.00	28dB

* Thermals Explained

 

Once again the NZXT Kraken X61 impresses and jumps to the top of the thermal benchmark chart! Beating our previous top performer, the Fractal Design Kelvin T12 and its maximum average core temperature of 53.75C (27.25C Delta) by 5.75C (3.25C Delta), with a chilly 48.00C maximum average core temperature and Delta of just 24.00C. You could of course argue that the Kraken X61 and its 280mm radiator is bound to be cooler than the Kelvin T12 and its tiny by comparison 120mm radiator, but it’s worth remembering that the little Fractal cooler beat every other cooler before it, including the 240mm radiator based liquid CPU coolers!

 

Acoustics

 

Of course with all that CPU cooling performance also comes a little noise. With the both NZXT FX V2 140mm Performance PWM Fans and the Kraken X61 pump set at 100%, the noise produced was a rather loud 51dB. Not something you’d want to hear whilst watching a film or web browsing at all, but certainly not disruptive when Gaming with a headset on. Outside of ultimate thermal performance mode and for when your browsing, we can select silent mode through NZXT CAM and suddenly the noise is more than halved to a far more ear and browsing friendly 25dB.

 

Final Thoughts

 

The pcG All-In-One liquid CPU cooler round-up continues forward with the biggest cooler in the NZXT line-up the NZXT Kraken X61, but does bigger necessarily mean better???

The NZXT Kraken X61 arrived at pcG within a large predominately white box. The front of which featured a huge image of the AIO CPU cooler hidden within. Once opened, we caught our first glance at the well protected Kraken X61 inside. Once removed from its packaging, the X61 was revealed to be well made with a subtle enough look to help it fit in with most Gaming rigs, without looking dull enough to easily be overlooked once installed. The 280mm radiator and
variable pump look good prior to installation, but throwing in the pumps colour customizable LED makes it look even better once installed and a cooler that is sure to fit in with any Gaming rig colour scheme at all.

Installation of the NZXT Kraken X61 into the pcG Test Rig was in all honesty one of the easiest installations I’ve ever come across (even despite its 280mm radiator!), so easy in fact that the Kraken X61 could potentially be fitted within a matter of minutes. Many AIO coolers that feature more than one fan, often feature various splitter cables to make up for multiple fans, or voltage reducing cables to slow down either the fans or sometimes even the pump. The Kraken X61 utilises something slightly different and actually has every cable you’d need pre-fitted to the pump block itself; a four way fan splitter, SATA cable for power, USB for readings and 3-pin plug for control. Personally I think this is a great touch and the cables provide enough length for even the biggest of PC cases. The cables themselves are also braided, but the braiding is of a very heavy duty nylon type which is pretty stiff and not as flexible as it could’ve been.

The biggest stand-out for the NZXT Kraken X61 is that of thermal performance. With the i5-4690K at its 3.5GHz stock speed, we recorded a maximum average CPU core temperature of 40.75C (16.25C Delta), sending it barging with its elbows out to the very top of the thermal benchmark chart. With the CPU voltage increased and a mild 4.0GHz overclock, we understandably gain a little heat, surprisingly not by a huge deal though, with an increase of 7.25C (7.75C Delta) taking it up to a maximum average CPU core temperature 48.00C (24.00C Delta). Which is once again at the very top of the charts! This is of course with the pump and fans set at 100% and kicking out 51dB of noise, which is nothing to really worry about when Gaming and wearing a headset, but for general browsing or watching media we can easily set the Kraken X61 to silent mode using the CAM software, to produce just 25dB of sound.

There is no doubt about it, the NZXT Kraken X61 offers the best thermal performance of any AIO liquid CPU cooler we’ve tested so far here at pcG. Combined with a very high build quality, possibly the easiest mounting assembly you’re likely to come across, the easy to use NZXT CAM software, customizable pump LED lighting and the possibility of near silent performance makes the NZXT Kraken X61 a sure-fire winner, or at least very nearly. The only stumbling block for me is the price… At a current price of approximately £120.00, the Kraken X61 is the most expensive AIO we’ve tested here and also one of the most expensive currently on the market. If you can get over that little stumbling block and want nothing but the best, you had better buy yours today!

 

Verdict

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Many thanks to NZXT for providing this sample for review