EK-Supremacy KIT H3O 360 HFX Review: Absolute Leader in Liquid Cooling

Today we will talk about a product, which proved to be the best liquid-cooling system of all we have tested to date. Unprecedented cooling efficiency, low level of noise, remarkable attention to every little detail, simple assembly and adequate price – these are just a few of the many advantages the new product from EKWB has to offer.

by Sergey Lepilov
11/08/2012 | 10:52 AM

A small Slovenian EKWB Company has been designing and manufacturing liquid-cooling components for PCs for thirteen years now. Over this period of time their product range grew from a few simple water blocks to the broadest assortment of parts for almost anything in this field. I would like to specifically stress that besides the primary products like huge radiators or flagship water blocks, EKWB pays special attention to every little screw in the direct and indirect meaning of this word. Moreover, they are very up-to-date and offer full-cover water blocks for contemporary graphics accelerators, which is a pretty challenging task, because they change even faster than CPUs and have different PCB layouts and designs.


The company is particularly proud of their complete liquid-cooling kits, which consist of carefully selected components. The prices of these kits depend on the components inside and vary between € 160 and € 270, but each kit contains everything you might need to build a highly efficient liquid-cooling system of superb quality. We received the most expensive flagship EK-Supremacy KIT H3O HFX for review. Let’s take a closer look at this product and check out how good it actually is.

Packaging and Accessories

EK-Supremacy KIT H3O HFX liquid-cooling system comes in a compact case-like packaging with a convenient plastic carry-handle:


The packaging is not really sophisticated in terms of design or the amount of additional information about the product printed on it. There is the model name, brief description of its key features and the list of compatible platforms printed on the orange and gray colored box. No flying dragons, frozen processors or futuristic girls – everything is very serious.

Inside the large box you can find all items and additional components in individual packaging:

Once you take everything out, it is really surprising how that much stuff could actually fit into a small box like this. Take a look what we found inside:

Here you can find a large radiator, three 120 mm fans, individual boxes with the pump, water block and expansion tank, a retention kit for the pump and a bunch of other accessories.

Among the “other” accessories we should mention a 2-meter long TUBE Masterkleer tubing with 10 mm internal diameter and 13 mm external diameter, eight EK-PSC nickel-plated compression fittings and a 100 ml bottle of the coolant concentrate:

The kit is made in Slovenia (some individual components are made in China) and its recommended retail price is set at € 270. It comes with a 5-year warranty.

EK-Supremacy KIT H3O 360 HFX Components

EK-CoolStream RAD XTX 360 Radiator and GELID Silent 120 Fans

The fundamental component of any liquid-cooling system is the radiator. EKWB engineers weren’t shy and bundled their kit with a large EK-CoolStream RAD XTX 360 radiator. It is packed into an individual box, which contains just as little information on it as the large box:


The radiator comes with two sets of screws and a guide warning you about possible radiator damage from the use of long screws:

EK-CoolStream RAD XTX 360 radiator is designed specifically for enthusiasts and is positioned for systems with very high heat dissipation from several different components at the same time. This is what it looks like:

As we can see, this radiator is pretty large. It measures 400x130x64 mm. You can take a closer look at the following layout schematics for more information:

EK-CoolStream RAD XTX 360 weighs almost 1.5 kg (1496 grams, to be more exact) and that is without fans or coolant. This is a truly massive product.

The radiator has classical design for its type: two aluminum side panels with thirteen copper channels and copper perforated “comb” soldered to them:

The actual radiator body is 50 mm wide and the large gaps between the copper comb fins make it ideal for high-speed as well as low-speed fan modes. The EK-CoolStream RAD XTX 360 radiator can accommodate up to six 120x120 mm fans. The thickness of the fans is only limited by the length of the retention screws and the fan manufacturers’ standards :)

There is a special hole at the top of the radiator, which can be used to pour the coolant in or out of the system:

There are two holes for G 1/4 fittings at the bottom of the radiator:

It is important to mention that the radiator is designed to withstand the pressure of 1 bar and if purchased separately EK-CoolStream RAD XTX 360 will cost you € 94.96.

EK-Supremacy KIT H3O HFX kit includes three EK-FAN Silent 120 fans 120x25 mm in size. They are packed in individual boxes with the same design as the rest of the liquid-cooling system components:

They look quite ordinary: black frame and black impeller with seven classically shaped blades:


If we take a closer look at the stator we can notice that the fans come from GELID – a cooling components maker we are very well familiar with already:

All three fans rotate with constant speed of 1600 RPM, although our monitoring tools reported the speed of 1460 RPM. These fans do not support PWM or any other rotation speed control methods. Besides, there are no cables, which could allow connecting all three fans to a single power and monitoring connector. This could be the only shortcoming we could find about EK-Supremacy KIT H3O HFX system. But, let’s not get ahead of ourselves here. Getting back to the fans, we should mention that their fluid dynamic bearing should last 50,000 hours or over 5.7 years of non-stop usage.

EK-Supremacy Water Block

As we have just seen, EK-Supremacy KIT H3O HFX kit has everything necessary to quickly dissipate the heat. Now let’s find out what they use to take the heat off the CPU. This function is performed by an EK-Supremacy water block that comes in an individual box:

It is bundled with four retention plates, two jet plates, a set of mounts, screws and springs, highly-efficient GELID GC-Xtreme thermal paste and an assembly and installation manual:

The water block looks simple but stylish: the semi-transparent acrylic top cover is decorated with nine embossed circles with the manufacturer logo sticker in one of them:


The base is covered with a paper sticker protecting it from accidental scratches and other damages. The base surface finish quality is excellent:

The hexagon L-shaped wrench included with the water block will allow you to take it apart completely:

Besides two silicone seals the water block consists of a copper base, a steel anodized jet plate and the above described acrylic top cover. The latter has very interesting internal configuration, where you can adjust the height of the central intake part:

You install one of the jet plates between the copper base and the top cover with an additional ring seal. The jet plates are all of different thickness. The default one already installed into the water block is the 0.8 mm thick J1 plate, which is considered to be universal. However, it is recommended to replace it with a 1.0 mm thick J2 jet plate for LGA 1155/1156 processors. The LGA 2011 processors should be used with the thinnest 0.7 mm J3 jet plate for the best cooling results:

This way EKWB engineers can control the height, at which the coolant is pushed into the water block and the coolant concentration volume upon entering the internal water block channels.

The water block base has micro-channel internal structure designed in the best traditions of liquid-cooling systems:

The 54 micro-channels in the water block base are of highest quality and precision.

I would also like to add that the contact surface of the water block base is exceptionally even, and the only reason why the thermal paste imprint is not perfect is the prominent heat-spreader of our test CPU:

EK-Supremacy water block can also be purchased separately for € 59.85.

EK-DCP 4.0 Pump and Retention Kit

The third component in the EK-Supremacy KIT H3O HFX liquid-cooling kit is the EK-DCP 4.0 pomp. It is also packed into an individual cardboard box:


It comes with a power cable, two plastic retention stands, double-sided sticky tape and pump installation and operation manual:

EK-DCP 4.0 is the most powerful pump from EKWB. Its performance is declared to be 800 l/h and the head (the number of meters the pump can raise the column of water at atmospheric pressure) – at 4 m. It looks like a simple plastic box 75x54x66 mm in size, which weighs 670 grams and has two threaded nozzles for fittings:


A small sticker with the pump marking indicates that its voltage is 12 V and current - 1.8 A:

As for other known characteristics of this pump, we should definitely mention the maximum noise level of 24.5 dBA and the 50,000 hours MTBF of the ceramic bearing. If purchased separately, this pump will cost you € 44.95.

Besides the pump, the EK-Supremacy KIT H3O HFX liquid-cooling kit also includes EK-DCP mounting plate KIT:

This kit consists of two thick but soft pads, a steel mounting plate, screws and installation instructions:

You should use this kit to install the pump anywhere you want. The shock-absorbing pads will lower the noise substantially.

EK-Multioption RES X2 – 150 Basic Reservoir

Finally, the last individual component in the EK-Supremacy KIT H3O HFX system is the EK-Multioption RES X2 – 150 Basic expansion tank (reservoir):


It comes with the retention, screws and plug-panels and an installation manual:

The cylindrical reservoir is 150 mm high, 60 mm in diameter and weighs 270 g. It is made of thick acrylic and has two plastic caps at the top and bottom:

There is one threaded hole in the top cap for the fitting, and three holes in the bottom cap, two of which are located directly at the base of the reservoir:


Besides, there is an additional tube 16 mm in diameter inside the reservoir, which serves as a sort of an anti-cyclone and prevents air bubbles from forming in the coolant. The installation procedure for the reservoir is described in detail in the enclosed instruction manual. EK-Multioption RES X2 – 150 Basic reservoir may also be purchased separately, in which case it will cost you € 32.95.

Compatibility and Installation

The first step during the system assembly and installation is the processor water block. EK-Supremacy is compatible with all contemporary platforms, and the replaceable retention plates and backplates included in the accessories bundle will ensure that the water block is securely fastened in systems with AMD as well as Intel processors. The installation for the LGA 2011 platform is super simple: you won’t even have to remove the mainboard from the system case. All you have to do is insert the mounting spindles into the retention holes in the socket plate and tighten the thumb-screws with springs evenly to secure the water block in place:

You won’t need any special tools here or for attaching any of the compression fittings.

The next step is to place all system components in convenient spots and connect them with tubes. The illustration below provides the preferable connection succession that will ensure maximum cooling efficiency:

Since we assembled EK-Supremacy KIT H3O HFX only for the current test session, we simply placed it next to the open system case:

Once we pumped the coolant through the system and removed all air bubbles from the contour, the coolant color changed gradually from light-green (as shown on the photo above) to clear-green. By the way, the coolant concentrate should be dissolved in 900 ml of distilled water and poured into the system through the hole at the top of the reservoir, for instance. We didn’t have any problems or difficulties during the assembly and installation of the EK-Supremacy KIT H3O HFX system.

Technical Specifications and Recommended Pricing


Testbed Configuration and Testing Methodology

We tested all coolers inside a closed system case with the following configuration:

For the primary tests and summary diagrams we overclocked our six-core processor with the clock generator frequency set at 125 MHz, the multiplier at 35x and “Load-Line Calibration” enabled to 4.375 GHz. The nominal processor Vcore was increased to 1.385 V in the mainboard BIOS. After that we tested the new coolers at even higher frequency and voltage settings. Turbo Boost was disabled during this test session, and Hyper-Threading technology was enabled to increase the heat dissipation. The memory voltage was at 1.65 V and its frequency was 2000 MHz with 9-10-10-28 timings. All other parameters available in the mainboard BIOS and related to CPU or memory overclocking remained unchanged.

All tests were performed under Windows 7 Ultimate x64 SP1 operating system. We used the following software during our test session:

So, the complete screenshot during the test session looks as follows:

The CPU was loaded with two consecutive LinX AVX test runs with the settings as indicated above. The stabilization period for the CPU temperature between the two test cycles was about 8-10 minutes. We took the maximum temperature of the hottest CPU core for the results charts. Moreover, we will also provide a table with the temperature readings for all cores including their average values. The ambient temperature was checked next to the system case with an electronic thermometer with 0.1 °C precision that allows hourly monitoring of the temperature changes over the past 6 hours. The room temperature during our test session varied between 20.8-21.1°C.

The noise level of each cooler was measured between 1:00 and 3:00 AM in a closed room about 20 m2 big using CENTER-321 electronic noise meter. The noise level for each cooler was tested outside the system case when the only noise sources in the lab were the cooler and its fan. The noise meter was installed on a tripod and was always at a 150 mm distance from the cooler fan rotor. The tested cooling systems were placed at the edge of the desk on a sheet of polyurethane foam. The lowest noise reading our noise meter device can register is 29.8 dBA and the subjectively comfortable noise level in these testing conditions was around 36 dBA (do not mix it up with low noise level). The fan(s) rotation speed was adjusted in the entire supported range using our in-house controller by changing the voltage with 0.5 V increment.

We are going to compare the cooling efficiency and noise levels of EK-Supremacy KIT H3O HFX liquid-cooling system against the Phanteks PH-TC14PE super-cooler with two default PH-F140TS fans:


Phanteks PH-TC14PE is currently the most efficient air-cooler out there, that is why it is particularly interesting to see how the EKWB liquid-cooling system can compare against it. Moreover, our summary diagrams will allow us to estimate the cooling efficiency of EK-Supremacy KIT H3O HFX compared against other liquid-cooling systems. The air-cooler was tested inside a system case with the removed side panel, i.e. in the exact same conditions as the EKWB system.

I would also like to add that the rotation speed of all fans was controlled using the same special controller I mentioned above with ±10 RPM precision. As for the system with EK-Supremacy KIT H3O HFX system inside, we used an additional 135 mm fan from Scythe rotating at 800 RPM for to cool the voltage regulator components around the processor socket.


Cooling Efficiency

The results of our cooling efficiency tests are given on the following diagram and in the following table:

Phanteks PH-TC14PE super-cooler has never been a “whipping boy” and looked quite worthy even facing a strong competitor like Swiftech H2O-220/230 Edge HD liquid-cooling system. But today is totally different. EK-Supremacy KIT H3O HFX is 10-11°C better than the best super-cooler making the distinction between superb liquid-cooling and exceptional air-cooling perfectly clear. At the same time, we understand that our six-core processor overclocked to 4375 MHz doesn’t allow the EKWB system to fully unwrap its potential. That is why we overclocked our CPU a little more – to 4500 MHz at 1.415 V Vcore and performed another round of comparative tests. Let’s take another look at the results in the following diagram and table:

The temperature difference between the EKWB system and the best super-cooler increased by another 1-2°C and EK-Supremacy KIT H3O HFX again demonstrated unprecedented performance in all fan modes. We can only admire a system with such high potential. But, trust me, this isn’t all. In the meanwhile, let’s add the new results into our summary table and diagram, where each cooler and liquid-cooling system were tested in their default configurations in quiet mode and at the maximum speed of the fan(s) with the CPU overclocked to 4.375 MHz at 1.385 V Vcore.

* - The peak temperature of the hottest CPU core is posted on the diagram taking

into account the difference from the current ambient temperature and is reduced to 25°C.

EK-Supremacy KIT H3O HFX system took over the top two lines having yielded less than 1°C to Swiftech H2O-320 Edge HD liquid-cooling system. The latter, however, wins only due to higher rotation speed of its cooling fans (2110 RPM vs. 1460 RPM by EKWB). In other words, Swiftech generates more noise. In quiet mode EKWB kit is an absolute and undefeated leader.

As for the maximum CPU overclocking results obtained using EK-Supremacy KIT H3O HFX system, we were able to maintain complete stability of our six-core processor at 4625 MHz frequency and 1.47 V Vcore. This is true for both: the maximum fan rotation speed as well as quiet mode at 600 RPM:

3 x 600 RPM

3 x 1460 RPM

Note that at 600 RPM the peak temperature of the hottest processor core reached only 69°C and at the maximum 1460 RPM of the EKWB’s fan – only 64°C. I have to admit: EK-Supremacy KIT H3O HFX continues to amaze us with its unprecedented cooling potential.

But again, this isn’t all. We decided to go all in and squeeze a few additional megahertz out of our processor, and… we did! Although we could only maintain stability at 1.515 V core voltage, which we normally do not recommend, but we managed to push our processor to 4750 MHz with only 69°C peak temperature:

3 x 1460 RPM

Now we should add the results of EK-Supremacy KIT H3O HFX to our overall rating chart for maximum processor overclocking:

No comments are necessary: absolute and undeniable total victory! Now let’s check out the acoustic performance of this system.

Acoustic Performance

We measured the noise level of our coolers throughout the entire speed range of their fans, as described in the chapter on testing methodology. Here are the results:

EK-Supremacy KIT H3O HFX has not only completely defeated Phanteks PH-TC14PE in cooling efficiency, but has also left it far behind in noise tests. This liquid-cooling system can be considered acoustically comfortable at up to 950 RPM speed of its fans, and quiet at up to 750 RPM. We have already said that EK-Supremacy KIT H3O HFX is exceptionally efficient at 600 RPM fan speed, which is barely audible at all. As for the pump noise, it would be incorrect to try and estimate it in our particular case, because we installed it temporarily and didn’t use the anti-vibration mounting kit. Nevertheless, even in this situation you could barely hear the pump at all.


Reviewers usually try to remain reserved and objective and prefer not to express any emotions or personal preferences towards the reviewed products. However, we are going to make an exception with the EK-Supremacy KIT H3O HFX system. It is a remarkable, excellent liquid-cooling product with the highest possible efficiency and very low level of noise! Once we checked out this system, familiarized ourselves with all its components and ran all the tests, we not just liked it, but fell in love with it in a way that only a true overclocker will understand. Moreover, the high price of this system becomes not even secondary, but the last thing you will consider after efficiency, noise, versatility, simple assembly and reliability topped with a five-year warranty.

Although almost everything included into the EK-Supremacy KIT H3O HFX system has been well thought-through, we would recommend EKWB to add such nice bonuses as manual or PWM adjustment of the fan rotation speed, a single fan cable, and a retention kit for the radiator could be attached to the system case. They could also give some thought to the possibility of making the pump power/noise adjustable, but this isn’t a critical thing at all. Everything else is impeccable and EK-Supremacy KIT H3O HFX system definitely deserves our Editor’s Choice title. If you are ready to invest € 270 into the best liquid-cooling system possible, then EK-Supremacy KIT H3O HFX is undoubtedly the one and only right choice.