EK Predator 240 AIO Cooler Review

This is an expensive all-in-one cooler directly from an old water-cooling shop. They make radiators, water blocks, reservoirs, pumps, tubing, fittings, kits – and now the Predator, available in 240 mm and 360 mm. EK bills this as “Pre-filled CPU Xpandable Liquid Cooling.” You can add an additional water block (EK suggests a GPU) and a reservoir. You could turn into a real water head. Today we have the 240 mm version in front of us. Does it live up to its heritage? Let’s see.



Air cooling vs water cooling. What’s the difference? We could talk about leaks, the joy of fiddling with technical things, but those are all peripheral. In air cooling, you transfer heat via a gaseous fluid in a heatpipe to a finstack, which then shifts the heat to air that moves through it. The heatsink could be passive or use one or more fans but the principal is the same. What limits a heatsink first is the contact surface and the TIM between the contact surface and the IHS. What limits a heatsink next is the ability of the heatpipes to transfer heat. Generally, soldered heatpipes do it better than clamped heatpipes, and more heatpipes means that more heat can be transferred. Some argue that fatter heatpipes can transfer more heat. Then there is the interface between the heatpipes and the fins, followed by the ability of the fins to conduct heat, the size of the fin stack (the area of the fins), the number of the fins and the ability of the fins to transfer heat to air. Nothing magic about this. Generally, the number of heatpipes and the surface area of the fins allows you to approximately predict the performance of a heatsink.

Water cooling uses a contact surface with TIM between that and the IHS, just like a heatsink. But instead of using a gaseous fluid confined to heatpipes, the water cooler uses a liquid fluid – usually not pure water – that runs through a water block that has the contact surface. The fluid runs through the water block. No clamped or soldered heatpipes. Then the fluid is pumped through hoses to a radiator, where it sheds its heat – just like a fin stack. And just like a heatsink, the larger the surface area, the more heat the radiator can shed. Consider that rads come in 120 mm and 140 mm for single fan rads, 240 mm and 280 mm for two-fan rads, and 360 mm and 420 mm for three-fan rads. Four-fan rads? I’ll let you do the math. There are also 92 mm and 80 mm rads for tighter confines.

So the big differences here are that the heatsink must shed its heat within the space around the CPU, while the water cooler moves the heat elsewhere and sheds it there. Because it does this it can utilize a much greater surface area to shed heat to air. Hence water-cooling systems tend to be able to accomplish more cooling than the best heatsinks. Again, no magic here. You will see below that EK reports their Predator with a three-fan rad cools appreciably better than their Predator with a two-fan rad.

But water systems may leak if assembled incorrectly, or if the materials are not up to the task. Hence EKWB’s focus on premium materials.

Introduction to EK Water Blocks

EK is from Slovenia, nestled in the Kamnik-Savinja Alps. I’ll give you a moment to look them up. It looks like a pretty place. The actual name of the company is EKWB, which stands for Edvard König Water Blocks. Here is a history, as told by EKWB:

  • In 1999, Edvard König bought his first computer. Soon he had realized that air cooling is not enough to cool his highly overclocked computer. So he tried to find an appropriate substitute. He found out about water cooling and shortly after he had a great desire to make his own water block. He spent days, nights and weekends developing sketches of water blocks.
  • In early 2003, Edvard’s dream came true. He finally designed and machined his first prototypes called the EK-1, EK-2 and EK-3. Edvard’s friend David joined the team to create their first CPU die simulator. Simulator helped the duo to find the best design with the tools they had at their disposal.
  • In 2003, Edvard designed the EK-4 from the experiences learned in the past.
  • By late 2003, the EK-6, derived from EK-4, became Edvard’s first mass produced CPU water block.

The history goes on from there. Now they sell a plethora of products. The Predator, in 360 mm and 240 mm, seem to be designed to win you over from air cooling to water cooling. In their printed promo material, EKWB say this about their new Predator line:

The reason we decided to enter this market is related to the fact that all AIO products on the market aim at the low cost segment, effectively ignoring the customers that would prefer build quality and expandability. That’s why we designed and made in Slovenia an ultimate AIO that uses same enthusiast level components as our Custom loops do. There were no compromises made and we think the [discerning customer] will appreciate that.

Price tag reflects the components costs as Predator 240 will go on sale for 199 USD/EUR. Still, we think customer spending several thousand euros on a PC would prefer to install AIO with quality parts, after all, it’s water inside 🙂

Features and Specifications of the Predator

The features of the Predator 240 mm from the product page:

HovercoreTM is a new, revolutionary design of radiator de-couplering that effectively prevents transfer of pump induced vibrations from the unit to the computer chassis itself, thus resulting in vibration-free and silent operation.

SupremacyTM MX CPU water block, top performer in Enthusiast segment, is specifically designed for Intel CPUs and offers great hydraulic and thermal performance. Carefully machined copper base is made from purest copper available and is further polished to absolute mirror finish. This alone greatly improves the cooling performance of the Predator.

CoolStreamTM PE 240mm radiator, has a full copper core superior to aluminum alternatives in terms of heat dissipation. In conjunction with EK-Vardar fans the result is increased performance across an entire fan operational range, thus delivering results both at low- and high airflow operation.

VardarTM fans – two on Predator 240 – are high-static pressure fans developed in-house specifically for liquid cooling systems. With low noise profile and PWM technology built in, the system always controls the RPM and keeps the fans silent while maintaining excellent cooling performance.

DDC pump is a powerful 6W liquid cooling pump providing 2-3x higher flow rate compared to other AIOs on the market. It’s also PWM controlled, allowing for automatic pump speed regulation depending on your CPU temperature. Full performance on demand or whisper quiet operation in idle mode!

Integrated Fan splitter hub reduces cable clutter and keeps the unit aesthetically clean. Predator pump and fans plug into the unit itself with only one PWM cable going into CPU Fan socket, while a single SATA molex cable powers the complete unit.

One note about “one PWM cable going into CPU Fan socket:” not all motherboards have a separate PWM channel for the pump. This obviates that.

Below is a diagram from EKWB showing the 240 mm Predator. It is available online for $199 + $29 shipping. Interestingly, the 360 mm Predator is available online for $239 + $32 shipping. As EKWB note in their enclosed materials, “the size of the radiator plays an important part in keeping the chip cool.” On their 5960K system, for example, the Predator 360 cools down to a net of 42.15 °C, where the Predator 240 cools to 46.43 °C.


Technical specifications (from the product page):

Model No

EK-XLC Predator 240


295 x 133 x 68mm (L x W x H)

Fan type

EK-Vardar F4-120ER Predator Edition (550-2200rpm)

Tube length

~400mm (15.75in)

Fitting type

EK-ACF Fitting 10/16mm

Coolant type

EK-Ekoolant EVO Clear

Pump type

Laing DDC3.1 6W

Total liquid capacity


CPU socket compatibility

– Intel LGA-1150/1151/1155/1156
– Intel LGA-2011(-3)


– EK-XLC Predator 240
– EK-TIM Ectotherm (1g syringe)
– Main Power and PWM signal cable
– Torx T20 key
– Installation manual (ENG)


Copper Plexi



Prepared for LED Diode




# of Fans


Although the Predator will not fit on an Intel 2011 socket out of the box, EK offers the LGA-2011 Screw Set, an add-on kit which allows for installation of EK-XLC Predator AIO cooler onto any LGA-2011(-3) motherboard.

Do you see any mention of a manual? Well, there is one – 24 pages, all in English (we would expect similar one-language manuals for other markets). It is explicit, and has lots of diagrams. The manual is online here. A “Check Compatibility list” is online as well; but as of this writing, it is not ready yet. Finally, there is an online installation guide (here) that is well worth watching. And last but not least there is an online configurator which will tell you which EKWB products support your equipment.


Inside the shipping carton, the EK Predator comes in a cardboard box covered but not cluttered with marketing. This is a clean look that is consistent with their website, an example of congruent design.

Front of Box
Front of Box

Back of Box
Back of Box

Inside you find a clamshell plastic packing structure that is clearly designed to defeat the inevitable shocks of international shipping. Again, the clean look extends to the physical packing.

Clamshell Packing
Clamshell Packing

Clamshell Opened
Clamshell Opened

Close Up with the EK Predator 240

Those are two thick-walled tubes. It is a miracle that they bend. They are not about to kink on you. And there are holes for another two fans. The water block is traditional. It is held on by four screws, like all water blocks. I have looked and have not found an exception to this: they all have four-point suspensions.

The small parts that come with the Predator 240 are simple – a SATA power supply cable, nine fan screws (they gave us an extra) to attach the fan side of the AIO to your case, an L-shaped torx wrench. And a 2-line cable for speed control and to report the RPM of one fan. It as a PWM plug at one end. At the bottom of the picture is the syringe of EK-TIM.

The EK Predator 240
The EK Predator 240

Small Parts
Small Parts

Finally we get a chance to see the Vardar fans that come with the Predator 240. These fans were designed in-house by EK specifically for rads, so EK reports that the fans have high static pressure. Note that these fans are pull fans. The AIO is fastened to your case with fan screws. Simple. Other systems are not so simple.

In the face-on picture, the pump is at the lower right corner. The reservoir is at the upper right corner. Reservoir? That’s right. This is a full water cooling system, and unlike other AIO systems it includes a reservoir.

Vardar Fans
Vardar Fans

Fans Face On
Fans Face On

The left picture of the Predator shows the pump and the reservoir. You can also get a clear view of the fittings. This is how you can add devices to your cooling system.

In the right picture is the other end, with fittings attached to the water block. The mounting screws are spring-mounted, to prevent the block from exerting too much force. Some systems use a torsion mechanism, trusting to the bending ability of the mount to exert the correct amount of pressure. This is better. There is also a refill plug with a 6 mm Allen wrench socket.

Pump and Reservoir
Pump and Reservoir

Water Block and Fill Plug
Water Block and Fill Plug

The first picture is a repeat of the previous, except now we ignore the heavy tubes and concentrate on the end. At the bottom we see a four-prong PWM connector. Since there is only one, you will need a PWM splitter to mount a third and fourth fan. The two-prong connector is the other end of the cable that goes to the main PWM header on your motherboard. It carries RPM and speed control signals. The 12 Volt current is carried by the socket at the lower right of the picture.

In the second picture, we have our closeup, this time from the exhaust side. The top green arrow marks the 12 Volt power socket. The middle blue arrow marks the two-prong connector carrying RPM and speed control signals. At the bottom, the red arrow marks the four-prong PWM fan connector.

Closeup of Waterblock
Closeup of Waterblock

Electrical Connections
Electrical Connections

Turning away from the radiator, we give our attention to the contact face of the water block. I subsequently rocked my razor on its surface. There was less than a quarter of a mm play across the whole surface. The contact surface is significantly larger than a modern CPU, so it is essentially flat. The convexity was enough to feel, just barely, but not nearly enough to show.

In the second picture I have focused the camera on what is reflected in the copper contact surface. What you are seeing is the ductwork on the ceiling of the basement. You could use this for a mirror.

Contact Surface
Contact Surface

Like a Mirror
Like a Mirror

Mounting the EK Predator 240

To mount the EK Predator, you first unscrew the screws that hold the backplate to the waterblock. There you will find a gasket as well as the backplate. Do not neglect the gasket. It keeps the steel backplate from shorting leads on the motherboard.

Next, you will use the included L-shaped torx wrench to take off the screws holding on the Intel standard backplate. Below is a picture of such a backplate.

Waterblock, EK Backplate and Gasket
Waterblock, EK Backplate and Gasket

Stock Backplate for 115x Scoket
Stock Backplate for 115x Socket

Now you can see what your motherboard looks like with the backplate removed. Scary, isn’t it? You can see some of the shortable leads that the gasket will protect.

The next picture shows the EK backplate in place. It has just one orientation that will allow it to be placed.

Stock Backplate Off
Stock Backplate Off

EK Backplate On
EK Backplate On

Below you can see what the screws look like, as well as a closeup of the torx wrench. You might wish to use this. My own torx wrench fits, but comes out easily. This one sticks firmly in place, so you can hold the screws as if the wrench were magnetized (it is not). Nice wrench. It makes removing and replacing the screws easier. Note the gasket.

Use the collared screw to anchor the clamp. When it is tight, you can position the backplate underneath so that the screw holes of the backplate can be seen through the screwholes of the motherboard. This makes reassembly much easier.

EK Backplate and Clamp Screws
EK Backplate and Clamp Screws

Socket Without Clamp
Socket Without Clamp

When the screws are tight, you can operate the clamp. Now this is a practice motherboard. It is a practice motherboard because the socket was damaged, as you can see. But note: the bottoms of Intel LGA chips are not flat. They contain an array of bumps. Normally, once a chip is down, you don’t disturb it. On the testing motherboard I had to remove the CPU chip to keep it from falling while I was removing the stock backplate and replacing it with the EK backplate. But the process of removing the chip might not leave your socket unscathed. Luckily this did not happen this time, or you would not be seeing the results below. But this is not what you would want for your chip, I think. The video guide EK made for this show them installing the backplate on a motherboard that still had it CPU socket cover on it. That implies a never-used motherboard. So this mounting system will probably work better if it is installed in a new system, and not retrofitted.

Clamp Attached
Clamp Attached

Clamp Attached
Clamp Ready for CPU

Here we can see the waterblock installed on the motherboard. A closeup shows the four-screw mounting system, as well as the paper cover: since this was a practice mount there was no need to remove it yet. One thing about this four-point mount: it is an ancient system. The whole water-cooling industry uses this old system. You may think that the entire industry could not be wrong, but I will remind you of the entire banking industry and 2008. We could also indicate the automobile industry and leaded gasoline. The point is, whole industries can be wrong.

Here, I demonstrated that to my own satisfaction. After getting the results you will see, I tried remounting the waterblock to see if I couldn’t squeeze a couple more degrees out of it. What EK tells you is true: the amount of TIM can result in wild temperature variation. But I discovered something more important. At one point I screwed down all four mounting screws tight. Then, as usual, I went around and tried them all again, for good measure. One of the “tight” screws had more tightening left to do. Had I not been so obsessive I would have missed it. Another user might have missed it and not gotten the cooling he or she expected.

Coming from air cooling, where the heatsink mounts vary greatly as the manufacturers try to find the right way to tighten a mounting with two screws without breaking the bank and running costs up, I find the classic waterblock mount to be utterly primitive – and this is one of the best of those. This may not concern you if you are used to water cooling, but the industry (EK included) is trying to entice users of high-end air to come over and try water. The four-point mount is not how to do it.

EK Predator on Motherboard
EK Predator on Motherboard

Closeup of Mounted Waterblock
Closeup of Mounted Waterblock

Testing Setup


Intel i7 4790K @ 4.5 GHz


Set to 1.23 Volts, reading up to 1.248 Volts.


Set to 1.8 Volts, reading down to 1.704 Volts


Intel HD Graphics 4600, integrated into the i7 4790k


Gigabyte Z97X Gaming-7


Crucial Ballistix Sport Ultra Low Profile; 2 x 4 GB, 8 GB total


Samsung 840 EVO’s, 500 GB + 1 TB


Seasonic SS-460FL 460W Fanless

Heat Stress Software

Linpack with AVX2 – LinX 0.6.5 user interface

Operating System

Windows 10, 64-bit

Core Temp Log

Real Temp

Ambient Temp Log

Digital TEMPer USB Thermometer, with logging software

Package Watt Log

Intel Power Gadget 3.0

Sound Pressure Meter

Tenma 72-942

EKWB provided the Predator 240. The heatsinks were provided by their respective OEM’s, except for a Prolimatech Megahalems, which was purchased retail at the end of 2009, with a Prolimatech Genesis and a Noctua NH-D14 SE2011 both purchased retail at the end of 2013. Each heatsink was mounted on the night before testing. This gave the TIM most of a day to do any migrating it was going to do.

Linpack runs in surges. When the temperature is graphed, you see ragged plateaus. In looking for cooling solutions, you want to know how well a heatsink cools those plateaus. So the temps under 70 °C (the valleys) are ignored in analyzing core temps.

Each test run was 30 minutes in duration. The last 20 minutes of each run was measured, and the core temperature logs were analyzed in Open Office spreadsheets. An Intel chip reports its temps in one degree increments, so for best accuracy these reports should be averaged in aggregate. Here the core temps were measured once a second, resulting in 1200-line spreadsheets.

The digital thermometer measuring air temp reported its measurements in increments of 0.1 °C. The ambient temperature was measured every five seconds, resulting in 240-line spreadsheets. The mean ambient temp was subtracted from the mean core temps, resulting in a net temp for each run. Finally, the three net temps were averaged.

The Sound Pressure level was measured 1 meter from the heatsink, with the motherboard set vertically, the way it would in your case. The ambient noise for this testing was 31 dBA. So the net SPL is the sound pressure level measured at 1 meter, less 31 dBA.

Results of Testing the EK Predator

As expected, the Predator topped the list. Perhaps surprisingly, it did not blow the competition away. EK tells us that the Predator 360 will cool several degrees better than a Predator 240 when they are on a 6-core CPU. So I decided to see if the 240 has cooling capacities at higher overclocks, so I went to 4.6 MHz and a Vcore of 1.25 to 1.28 Volts. All ended in a black screen of death – a hard restart, despite increasing the Vcore. Linpack with AVX2 is hard on a chip, so I let the OC go. But I observed the temperatures in real time. At the elevated Vcores, the temps were proportional to what we have here. So overclocking another 100 MHz would require a Vcore that is high enough that the elevated temp would throttle the CPU. In other words, this overclock is as high as we can expect with Linpack + AVX2.

The results at 4.5GHz:


The bottom line is that this cooler, with a nearly flat contact surface that is held down by spring-loaded screws, the Predator 240 cools nearly 5 °C better than the next best spring-loaded heatsink, the NH-D15. Outstanding results, indeed.

Oh, yes: I tried to hear the pump. I really tried. I couldn’t do it. I knew the pump had to be running, since the cooler was cooling. But I couldn’t hear it. Likewise, I couldn’t hear the waterblock.

EKWB Predator 240 Conclusions

You would have to have this beast in your hands to understand that EKWB weren’t kidding when they talked about “quality parts” and “no compromises made.” They weren’t kidding. This is one premium water cooling system. Talk on the web emphasizes the quality of the tubing, the rad, the waterblock and the fans. The rad certainly has a following. And the Vardar fans have gotten fairly well known among enthusiasts. You’re not going to hear the pump or the waterblock. And how many AIO systems have a reservoir? And then the literally mirror-like nearly-flat contact surface. And the spring-loaded screws to assure proper contact without being excessive. Finally, the cooling results. This is the rare system that is good enough to deserve its rarefied price.

When they come down from max revs (here above 2000 rpm) the fans get awfully quiet awfully quickly. At idle, you can’t tell whether they are running unless you look to be sure.

Now let’s discuss the mount. Apparently EKWB has been having their users remove the stock backplate for a long time. Yet in the air cooling world, nobody asks you to undo those three screws on the clamp to take off the stock backplate. If you approach this task with some trepidation, that just shows your good sense. You may wish to pass on this system for a retrofit if you are not brave (or foolish). This is no way to get airheads to convert over to water. Like heatsinks, this AIO could adopt a system that does not require removal of the clamp screws.

The water-cooling industry universally employs the archaic 4-point mounting system. Quite a few heatsinks (air coolers) use a two-point system that avoids user mistakes in tightening. EKWB cannot be faulted here for using an industry standard. Yet their own history says their founder began his business to improve the state of the art. Maybe it is time for EKWB to turn their attention to mounting. A quality product like the EK Predator deserves a quality mount.

Maybe it is also time to change the written directions a little bit. “Two rice grains” is awfully imprecise. Wet rice or dry rice grains, for example? The phrase also does not describe the EK-TIM, which comes out as a round pool of near-liquid – not in a line. EKWB should specify the diameter of the optimal size of the TIM pool in mm. You may need to dismount and remount the EK Predator to find the best mount. Luckily, once the backplate is in place this is easy to do – one of the few advantages of EK’s mounting system.

But these are just quibbles. The EK predator is a fine AIO, and one that can be expanded.

Availability and Choice of AIO

The EK Predators are available online, shipped from EKWB (see above), at Performance PC’s, and at Amazon (with free shipping). The Amazon listing is sold by Altex Electronics. All prices are at list. If you have a 4-core CPU and don’t plan to expand, you could get the Predator 240. But for $40 more you can get the EK Predator 360, which will allow you to expand your system and not notice any diminution in your cooling.

EK Predator 240 Pros

  • Top Cooler
  • Quiet
  • Solid
  • Constructed of excellent materials
  • System includes a reservoir
  • Nearly flat contact surface will not deform your CPU
  • Copper contact surface – no nickel plating between it and the IHS
  • Spring-mounted hold-down screws
  • Excellent Manual. Comprehensive and full of Diagrams. No stinting, large and all in a single language.
  • Manual is available online
  • Video Installation Manual is excellent and available online.
  • The website is pleasant and easy to navigate
  • Easy-to-use online configurator
  • You cannot hear the pump
  • The fans are PWM
  • Pump and fans are on the same PWM line

EK Predator 240 Cons

  • You must disassemble the clamping mechanism and use the standard EK backplate
  • Directions are a little unclear on just what amount of TIM you should use.

Click the stamp for an explanation of what this means

Ed Hume (ehume)

About Ed Hume 75 Articles
Ed Hume has been a contributor to the Overclockers.com community for over 10 years. He has written nearly 100 reviews and guides mostly focused on cooling. His scientific and technical approach to analyzing airflow, temperatures, heatsinks and fan performance have made him a fan favorite. In one of his well-known fan roundups, he compared the performance of over 60 fans at once, now that's dedication to the craft!

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Avatar of Janus67

Benching Team Leader

17,239 messages 564 likes

Great review Ed!

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Avatar of GTXJackBauer

Water Cooling Senior Member, #TEAMH20HNO

6,799 messages 0 likes

Yeah, nice review. :thup:

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Sim Racing Aficionado Co-Owner

23,911 messages 404 likes

Any word on release date of add-on parts?

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Avatar of Eddie Current
Eddie Current


159 messages 0 likes

Good Job, nice product.

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Avatar of ehume


874 messages 1 likes

Any word on release date of add-on parts?

No. But I would ask them directly.

This AiO is marvelous to have in your hands. It seems like you can feel the quality. It almost seems like a shame to mount it and turn your back on it. But be wary of the case you put it in. I just tried it in the Silent Base 600. It won't fit.

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Avatar of SF101

The Printer Guru

1,721 messages 54 likes

I wonder how it stacks up against swiftech's offerings which as similar mindset wise.

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Sim Racing Aficionado Co-Owner

23,911 messages 404 likes

I wonder how it stacks up against swiftech's offerings which as similar mindset wise.

Temps are very similar, within +/- 1-2°C of each other.
The Swiftech H220-x and H240-x are incredibly quiet, I'd say +/- 3dBa depending on the review from the Predator.

Basically, a wash. Except that the Swiftech H220-x is $60 cheaper than the Predator 240.

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Avatar of mimart7


943 messages 0 likes

A friend has the Predator 360, and they are thrilled with the performance. The one benefit of the EKWB kit, is that you are not prevented from doing a push/pull configuration. Both Swiftech and EKWB make great kits, and it's a toss up, imho.

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Avatar of HankB


1,221 messages 20 likes

Thanks for the review. Every once in a while I think about going to water cooling. Before this review and the comments I was only aware of (what I think of as) low end AIOs and custom high end setups. These high end AIO setups seem to offer the performance of a custom setup (albeit w/out GPU cooling) with the convenience of an AIO. Do I have that right?

Any concerns about future proofing? I suppose anything I buy today would support the current configurations (1150 today, perhaps 1151 next?) If I skip the next generation of sockets, how likely is this to fit the subsequent generation?

Maybe I need to start hanging around the cooling forum a little more. ;)

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Avatar of Janus67

Benching Team Leader

17,239 messages 564 likes

I imagine it would be pretty likely for intel, as they have been good about cooling socket holes. Who knows what amd will bring with Zen though.

These kids are also expandable to add a gpu as long as you add more radiator

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