NZXT Kraken X40 CPU Cooler Review
By Rafael Coelho on January 31, 2013


Introduction

Hardware Secrets Silver Award

The Kraken X40 is a sealed liquid cooling system for CPUs, with a 140 mm radiator cooled by a 140 mm fan. Check it out!

The highlights of the Kraken X40 are the 140 mm radiator and fan (most similar products use a 120 mm radiator and fan), and a USB interface that allows you to control and monitor the temperature and the pump and fan speeds through the computer.

Figure 1 shows the box of the NZXT Kraken X40.

NZXT Kraken X40
click to enlarge
Figure 1: Package

Figure 2 shows the contents of the box: the radiator-block set, fans, manuals, driver and utility disk, and installation hardware.

NZXT Kraken X40
click to enlarge
Figure 2: Accessories

This watercooler is discussed in detail in the following pages.

The Radiator

The sealed radiator-block system is shown in Figure 3. At the left is the radiator; at the right is the block.

NZXT Kraken X40
click to enlarge
Figure 3: Sealed system

Figures 4 and 5 reveal the radiator of the NZXT Kraken X40. The radiator seems to be thinner than those that we are accustomed to seeing, but this is because it is bigger than common 120 mm radiators. It measures 5.4 x 6.8 x 1.1 inches (138.4 x 172.5 x 27.0 mm).

NZXT Kraken X40
click to enlarge
Figure 4: Radiator

NZXT Kraken X40
click to enlarge
Figure 5: Radiator

Block and Fan

The block, with the integrated pump, is shown in Figure 6. The manufacturer’s logo at the top is illuminated by internal LEDs, and you can choose the color of the light.

NZXT Kraken X40
click to enlarge
Figure 6: Block

The base of the block, which is made of copper, is revealed in Figure 7. The thermal compound comes pre-applied.

NZXT Kraken X40
click to enlarge
Figure 7: Base

Figure 8 shows the cables of the block. There is one three-pin connector that must be connected to the “CPU cooler” header of the motherboard, in order to power the system and tell the fan speed to the motherboard. It would be better if the system were powered directly by the power supply, especially if you plan to use two high-power fans. There is also a USB cable and two connectors for fans.

NZXT Kraken X40
click to enlarge
Figure 8: Block cables

Figure 9 illustrates the 140 mm PWM fan that comes with the Kraken X40.

NZXT Kraken X40
click to enlarge
Figure 9: Fan

Installation

In Figure 10, you can see the frame, backplate, and screws for use with sockets LGA1155, LGA1156, LGA1366, and LGA2011. There is a similar set of parts for use with AMD processors. Figure 11 shows the frame mounted on the block.

NZXT Kraken X40
click to enlarge
Figure 10: Mounting hardware for Intel CPUs

NZXT Kraken X40
click to enlarge
Figure 11: Frame assembled

After assembling the frame on the block, install the system inside your case. Figure 12 shows the Kraken X40 installed in our system, with the radiator at the top panel of the case.

NZXT Kraken X40
click to enlarge
Figure 12: Installation finished

The software that controls the Kraken X40 comes with the product. The fan (or fans, if you install a second one) can be configured for three operating modes: Extreme, Silent, or Custom, where you can program a fan power versus temperature curve. The color of the LEDs at the block can also be configured. Figure 13 shows the application screen.

NZXT Kraken X40
click to enlarge
Figure 13: Application screen

We tested the Kraken X40 in two modes: Silent and Extreme.

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

Software Used

Error Margin

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

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.

CoolerRoom Temp.NoiseSpeedCore Temp.Temp. Diff.
Cooler Master Hyper TX318 °C50 dBA2850 rpm69 ºC51 °C
Corsair A7023 °C51 dBA2000 rpm66 ºC43 °C
Corsair H10026 °C62 dBA2000 rpm64 ºC38 °C
EVGA Superclock26 °C57 dBA2550 rpm67 ºC41 °C
NZXT HAVIK 14020 °C46 dBA 1250 rpm65 ºC45 °C
Thermalright True Spirit 12026 °C42 dBA1500 rpm82 °C56 °C
Zalman CNPS12X26 °C43 dBA1200 rpm71 °C45 °C
Zalman CNPS9900 Max20 °C51 dBA1700 rpm62 °C42 °C
Titan Fenrir Siberia Edition22 °C50 dBA2400 rpm65 °C43 °C
SilenX EFZ-120HA518 °C44 dBA1500 rpm70 °C52 °C
Noctua NH-L1220 °C44 dBA1450 rpm70 °C50 °C
Zalman CNPS8900 Extreme21 °C53 dBA2550 rpm71 °C50 °C
Gamer Storm Assassin15 °C48 dBA1450 rpm58 °C43 °C
Deepcool Gammaxx 40015 °C44 dBA1500 rpm60 °C45 °C
Cooler Master TPC 81223 °C51 dBA2350 rpm66 °C43 °C
Deepcool Gammaxx 30018 °C43 dBA1650 rpm74 °C56 °C
Intel stock cooler18 °C41 dBA2000 rpm97 °C79 °C
Xigmatek Praeton19 °C52 dBA2900 rpm83 °C64 °C
Noctua NH-U12P SE218 °C42 dBA1300 rpm69 °C51 °C
Deepcool Frostwin24 °C46 dBA1650 rpm78 °C54 °C
Thermaltake Frio Advanced13 °C56 dBA2000 rpm62 °C49 °C
Xigmatek Dark Knight Night Hawk Edition9 °C48 dBA2100 rpm53 °C44 °C
Thermaltake Frio Extreme21 °C53 dBA1750 rpm59 °C38 °C
Noctua NH-U9B SE212 °C44 dBA1700 rpm64 °C52 °C
Thermaltake WATER2.0 Pro15 °C54 dBA2000 rpm52 °C37 °C
Deepcool Fiend Shark18 °C45 dBA1500 rpm74 °C56 °C
Arctic Freezer i3013 °C42 dBA1350 rpm63 °C50 °C
Spire TME III8 °C46 dBA1700 rpm70 °C62 °C
Thermaltake WATER2.0 Performer11 °C54 dBA2000 rpm49 °C38 °C
Arctic Alpine 11 PLUS11 °C45 dBA2000 rpm82 °C71 °C
be quiet! Dark Rock 210 °C41 dBA1300 rpm58 °C48 °C
Phanteks PH-TC14CS16 °C47 dBA1300 rpm58 °C42 °C
Phanteks PH-TC14PE16 °C48 dBA1300 rpm57 °C41 °C
SilverStone HE01 (Q)19 °C44 dBA1150 rpm63 °C44 °C
SilverStone HE01 (P)20 °C57 dBA2050 rpm62 °C42 °C
Thermaltake WATER2.0 Extreme (S)17 °C44 dBA1250 rpm52 °C35 °C
Thermaltake WATER2.0 Extreme (E)17 °C53 dBA1900 rpm50 °C33 °C
Deepcool Neptwin11 °C46 dBA1500 rpm56 °C45 °C
SilverStone HE0219 °C49 dBA2000 rpm64 °C45 °C
Zalman CNPS9900DF23 °C45 dBA1400 rpm68 °C45 °C
Deepcool ICE BLADE PRO V2.022 °C43 dBA1500 rpm67 °C45 °C
Phanteks PH-TC90LS24 °C47 dBA2600 rpm95 °C71 °C
Rosewill AIOLOS20 °C40 dBA1600 rpm94 °C74 °C
Corsair H6020 °C49 dBA2000 rpm64 °C44 °C
Zalman LQ31027 °C51 dBA2050 rpm65 °C38 °C
Noctua NH-L9i24 °C44 dBA2500 rpm95 °C71 °C
NZXT Respire T4020 °C45 dBA1850 rpm76 °C56 °C
NZXT Respire T2021 °C45 dBA1900 rpm77 °C56 °C
Zalman LQ31520 °C52 dBA1950 rpm57 °C37 °C
Corsair H80i (Quiet)19 °C44 dBA1100 rpm61 °C42 °C
Corsair H80i (Maximum)19 °C57 dBA2500 rpm55 °C36 °C
NZXT Kraken X40 (Silent)25 °C44 dBA1050 rpm66 °C41 °C
NZXT Kraken X40 (Extreme)25 °C53 dBA1650 rpm62 °C37 °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.

NZXT Kraken X40

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

NZXT Kraken X40

Main Specifications

The main specifications for the NZXT Kraken X40 CPU cooler include:

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

Conclusions

The NZXT Kraken X40 proved to be an excellent liquid cooling system for CPUs. It performed wonderfully in the Extreme mode, and combined high cooling performance with low noise level in the Silent mode. The product is well-made and has an excellent overall quality.

The only issue about the Kraken X40 is about the compatibility with your case: several cases available nowadays only have openings for 120 mm fans at the rear and top panels, and the Kraken X40 needs a 140 mm fan opening. However, if your case supports 140 mm fans, the Kraken X40 will fit perfectly.

Being a great liquid cooling system, with excellent performance and flexibility, the NZXT Kraken X40 receives the Hardware Secrets Silver Award.

Originally at http://www.hardwaresecrets.com/article/NZXT-Kraken-X40-CPU-Cooler-Review/1714


© 2004-14, Hardware Secrets, LLC. All Rights Reserved.

Total or partial reproduction of the contents of this site, as well as that of the texts available for downloading, be this in the electronic media, in print, or any other form of distribution, is expressly forbidden. Those who do not comply with these copyright laws will be indicted and punished according to the International Copyrights Law.

We do not take responsibility for material damage of any kind caused by the use of information contained in Hardware Secrets.