I remember just over 5 years ago at CES was the first time I had ever seen a sealed water cooling system. At the time, it seemed a little crazy. How would it fit various PCs? What about maintenance? At that time the only real options were custom setups using parts designed for fish tanks. That company introduced their kit later on (Cool-It’s Domino), it had its share of problems, not to mention trying to convince people you weren’t crazy when you said you want to put water inside of their PC. Years later it feels like everyone has gotten into the market and those designs have improved year after year. Cooler Master for the last few years has been trying there hand at it. Today I have the chance to dig in check out their latest model, the Nepton 240M. They have had a few Nepton models before but this is the first 240mm model.

Product Name: Cooler Master Nepton 240M

Review Sample Provided by: Cooler Master

Written by: Wes

Pictures by: Wes



CPU Socket

Intel LGA 2011-3 / 1366 / 1150 / 1156 / 1155 / 775

AMD Socket FM2 / FM2+ / FM1 / AM3+ / AM3 / AM2+

Pump Dimensions

75 x 69.8 x 49.1 mm ( 3 x 2.7 x 1.9 inch )

Radiator Dimensions

120 x 240 x 27 mm

Radiator Material


Fan Dimensions

120 x 120 x 25 mm ( 4.9 x 4.9 x 1 inch )

Fan Speed

800~2400 RPM (PWM) ± 10%

Fan Airflow

16.4-76 CFM ± 10%

Fan Air Pressure

0.47~4.8 mmH2O ± 10%

Fan Life Expectancy

160,000 hours

Fan Noise Level

6.5 – 27 dBA

Fan Bearing Type

Rifle bearing

Fan Connector


Fan Rated Power

12 VDC / 0.4A / 4.8W

Pump Life Expectancy

70,000 hours

Pump Rated Voltage



Packaging and Photos

No huge surprises, the Nepton 240M has the purple/black theme that all non-Storm Cooler Master products have. On the front of the box you have a photo of the water cooling, a 5 year warranty badge, and three budges highlighting features. On the back Cooler Master put a line drawing of both the pump and radiator, this is great if you are concerned that the kit might not fit in your build. They also include a graph showing the performance that you might expect. Other than that there isn't too much else going on the back of the box, but you get everything you need. For those, like me, who like to see specifications as well, Cooler Master also slipped them into the side of the box.

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Inside the box everything is wrapped up in their own individual plastic bags and then placed in a formed cardboard tray to keep it all safe. 

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Along with the radiator/pump you also get a warranty information paper and an instruction book. All of the accessories come wrapped up in a Ziploc like bag. You get a 240mm rubber mount to keep the Nepton's fans quiet. You also get mounting kits for both Intel and AMD and also specific screws for Intel 2011 sockets as well. There is also a short four pin fan splitter so you can hook both fans up and know they are running the same speed.

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The Nepton’s radiator is slightly thicker than some of the other sealed kits that I have had in but it is still a little thinner than what the average custom loop’s radiator would be. That said I really like that Cooler Master slipped the small logo onto the side of the radiator, when installed this along with the logo on the pump should show off what you have.

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So speaking of the pump/water block of the Nepton 240M. What you get is noticeably thicker than all of the other sealed kits. Those of you hoping to pack this into a very small form factor may have to keep that in mind, but for most people a little thicker on the pump isn’t going to get in the way of anything. On top of the pump Cooler Master slipped in a backlit Cooler Master logo. I think it looks good, but if you are looking for something a little more subtle, it may not work for you. In the shots below we can see the FEP tubing. Each line attaches to the pump with a 90-degree fitting that moves slightly. On the bottom side I wasn’t really all that impressed with the surface of the water block. The copper plate is large but the finish is a little rougher than I would prefer, you will most likely be able to edge out a little more performance by polishing this later on.

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The Nepton 240M comes with two 120mm Silencio fans. They run between 800 and 2400 RPM and are both PWM fans. Cooler Master is saying that the fans pull 4.8 watts each and put out a maximum of 27 dBA. The Silencio fans look a little different from the rest of Cooler Masters product lineup, the fan blades extend around more than most fans giving them a twisted look. What I did find interesting, if you look the fan cords, the start as the thin all black cables that I love but they wrapped them in sleeving over top of that. If they used standard bright cables I would prefer sleeving, but in this case I would rather go with the plain cable. 

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Our Test Rig and Methodology

Cooling Test Bench


Intel Core i5-2500

Live Pricing


Asus Sabertooth P67

Live Pricing


Seagate Barracuda ES.2 1TB

Live Pricing


Kingston HyperX DDR3 1600MHz 8GB

Live Pricing

Video Card

NVIDIA GeForce GTX 760

Live Pricing


Cooler Master xB

Live Pricing


Windows 7 Home Premium x64

Live Pricing

Thermal Paste

Noctua NT-H1

Live Pricing

Cooling Tests Ran

Peak Test

Prime95 for a total of 30 minutes at 100% fan speed

Real World Test

3DMark 11 Combined Test for a total of 30 minutes at 100% fan speed

Noise Testing

Noise level measurements taken with a digital sound level meter every 10 minutes throughout the test to be averaged into an overall comparison score



Without a doubt over the past few years manufactures have made major improvements in the brackets for water cooling kits. It used to be a two person job to install a kit because you needed to hold the rear bracket, hold the pump, hold the radiator out of the way and also screw in the screws at the same time. For the Nepton 240M things went much easier than that, without an extra set of hands even. Cooler Master has you install the back plate first, attaching it to your motherboard using the same tall bolts that the pump also screws into. From there you need to install two brackets onto the pump. The brackets have the screws and springs built in already. With those installed you just make sure you have thermal paste (it comes with the kit, you just have to apply it) and screw all four screws down.

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From there you will need to install the two fans onto the radiator. Depending on your case configuration you might be installing using longer screws that also attached the radiator to your case or you might install the fans using shorter screws and then install the fans/radiator combination using small screws into the back of the radiator. Both are easy to do and both types of screws are included. From there you need to plug in the fan plug from the pump into the CPU fan header on your motherboard and then use the included fan cable splitter to combine the two fan cables into one to plug into your second CPU fan header. The installation shouldn’t take more than 20 minutes assuming you can get to the back of your motherboard and you can expect both Intel and AMD installations to be similar only with different backplates and pump brackets.

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Full disclosure. While the installation ended up being easy. I did run into a few issues with the installation kit from Cooler Master. My initial kit ended up stripped out because the screws on the Intel mounting kit had jagged ends on them, causing them to cross thread. This type of thing happens sometimes and it wouldn’t even be worth mentioning but on my second kit the screws had a similar end on them and this time there were additional problems. The preassembled screw/spring design on one of the Intel brackets had come apart in shipping. Putting it back together wouldn’t be an issue if they used a C clip but they use a full O clip so I did have to work hard to get it back together. After that I found out that one of the plastic clips for the backplate was also missing in our second kit. SO in the end, the installation isn’t bad assuming you have everything you need. If you pick up a 240M I would suggest checking to make sure all of the parts are in there and in good shape before starting on your installation. This was most likely just an issue with the batch that they got in for marketing, but if it isn’t I want to make sure people know to look for it.



With the Nepton 204M installed in our test bench I was finally able to get to testing. To do this we run through two different benchmarks. One is Prime95, this benchmark puts the CPU under more load than you should ever see in day to day use. The second test is running through the combined test on 3DMark 11 on loop. This way we are loading both the CPU and GPU to see what a more real world situation will put out for heat. With both tests I document both the CPU and RAM temps because in configurations heatsinks do a better job cooling RAM as well. Along with that testing I also document the noise levels to see how quiet everything runs.

It wasn’t really a big shock when the Nepton 240M out performed everything else we have tested in the past including the other 240mm water cooling kit from Cooler Master. On the ram side of things peak temperature testing did show that the Nepton 240M had a little room for improvement but really that is more specific to where the water cooling is installed in our test bench than anything else. The Be Quiet heatsink that performs best on that test does blow down on the ram were the Nepton 240M blows across the motherboard in our configuration.





Noise testing was a little less impressive but for full disclosure with this being the first time I had performed these tests in the LanOC office (previously they were done by our old cooling reviewer remotely) it is very possible that I didn’t have the decibel reader in the same location as before. This is important because even just a few inches can change the readout by a large amount. Because of that I’m inclined to ignore this result until I do father testing and retesting on other heatsinks.



Overall and Final Verdict

So at the end of the day is Cooler Masters new Nepton 240M the kit to go with? Well its performance was top notch in all of my testing. The kit was easy to install (assuming you get all of the parts). I also really like that Cooler Master backlit their logo on the pump as well. I really didn’t have much to complain about during the entire process other than the potential quality issue I ran into with the installation kits. Basically assuming that the two issues I ran into aren’t an issue with other product kits I would keep this near the top of my list when shopping for water cooling. I love that Cooler Master continues to improve on their water cooling designs. This helps keep completion in the market, especially with the OEM manufactures of most water cooling kits locking most people out with patents.


Author Bio
Author: garfi3ldWebsite: https://lanoc.org
You might call him obsessed or just a hardcore geek. Wes's obsession with gaming hardware and gadgets isn't anything new, he could be found taking things apart even as a child. When not poking around in PC's he can be found playing League of Legends, Awesomenauts, or Civilization 5 or watching a wide variety of TV shows and Movies. A car guy at heart, the same things that draw him into tweaking cars apply when building good looking fast computers. If you are interested in writing for Wes here at LanOC you can reach out to him directly using our contact form.

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garfi3ld's Avatar
garfi3ld replied the topic: #35947 05 Dec 2014 20:42
Before your weekend you might want to check out the 240mm water cooling kit from Cooler Master that I take a look at today. Have a great weekend!

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