420mm AIO CPU Coolers represent the pinnacle of AIO liquid cooling technology, offering unprecedented performance. Of course, the perceived performance of 420mm coolers alone is not enough to blindly pick any option without any prior research. It is imperative to weigh every aspect of a cooler to get an option that caters to your personal requirements. That is why I have compiled a comprehensive guide going through the Best 420mm AIO CPU Coolers.
Take a look at my selection of the best 420mm AIO, all compared with each other:
Last update on 2024-03-03
Best 420mm AIO CPU Coolers
Here are the Best 420mm AIO CPU Coolers:
- Alphacool Eisbaer Aurora 420
- CORSAIR iCUE H170i Elite LCD XT
- ARCTIC Liquid Freezer II 420
- Silverstone IceMyst 420
Alphacool Eisbaer Aurora 420
Best Overall 420mm AIO CPU Cooler
Cooler Type: 420mm AIO Liquid Cooler | Radiator Dimensions (LxWxH): 458 × 144 × 30 mm | Fans: 3x 140mm Fans | Fan Speed: 1500 RPM | Noise Level: – | Socket Support: Intel LGA 2066, 2011-v3, 2011, 1700, 1200, 1151, 1150, 1155, AM2, AM2+, AM3, AM3+, FM1, FM2, FM2+, AM4 | RGB: Yes
- Beastly cooling performance
- Copper radiator
- Reduced noise levels
- Inconvenient installation
Alphacool is revered as a cooler manufacturer, with their contributions remaining prevalent throughout the community. Their Eisbaer Aurora series has been featured in numerous articles for their exceptional cooling performance and great build quality. The 420mm variant is one of the higher-end offerings in the series.
Cooling Performance: The Alphacool Eisbaer Aurora 420 is equipped with three AURORO LUX Pro 140mm fans that are capable of reaching a maximum fan speed of 1500 RPM. These fans also feature seven blades in total while generating an airflow of 71 m³/h. Moreover, Alphacool has made use of their DC-LT2 pump, which provides a maximum operational speed of 2600 RPM. Lastly, Alphacool has kept the fin density at 16 FPI for an optimal cooling experience.
Build Quality: Build quality on the Alphacool Eisbaer Aurora 420 is nothing short of remarkable. It comprises a metallic housing for the radiator, a copper fin stack, and a total of 12 channels designated for coolant flow. Similarly, the fans are also well-constructed, enclosed in a thick ring-shaped frame that is bolstered by anti-vibrational pads on all four corners.
Aesthetics: Aesthetically, the Eisbaer Aurora 420 is not vastly different from its predecessors. You get a similar-sized pump reservoir combination along with RGB lighting on top. Lighting on the fans is managed through the dual rings present on the actual frame, which allow for a much better illumination than standard LED lights. It is worth mentioning that lighting can be controlled using the included controller or third-party software.
Noise Level: While Alphacool has not provided a concrete statement about the noise levels of the fans on their official websites, they remain reasonably low for the most part. This claim is further substantiated by Alphacool’s statement about their pump’s lower noise output in comparison to its predecessors.
Value For Money: Despite coming with a host of note-worthy features and design elements, Alphacool does not charge an extraordinary amount for the Eisbaer Aurora 420, with the price tag remaining primarily in line with the performance it offers. Its value for money is only further reinforced through the presence of a copper radiator, included controller, and lower noise outputs.
Buy It If:
You want the ideal 140mm cooler: Packed with powerful 140mm fans and Alphacool’s DCLT 2 pump, the Alphacool Eisbaer Aurora 420 provides impeccable cooling performance without compromising on build quality, appearance, or noise levels.
Don’t Buy It If:
You want convenient installation: Requiring 17 parts for the installation of the CPU block, setting up the cooler can be a hassle, especially for beginners.
What Makes It The Best Overall 420mm AIO CPU Cooler?
The Alphacool Eisbaer Aurora 420 comes with decently powerful AURORA LUX Pro fans, a capable pump, and robust build quality without costing an egregious amount. Adding on to that, the cooler also does not disappoint when it comes to aesthetics, making it the Best Overall 420mm CPU Cooler.
More From Alphacool:
- ALPHACOOL Eisbaer Pro AURORA 420
- ALPHACOOL Eisbaer Pro AURORA 360
- ALPHACOOL Eisbaer Pro AURORA 280
- ALPHACOOL Eisbaer Pro AURORA 240
CORSAIR iCUE H170i Elite LCD XT
Best Performance 420mm AIO CPU Cooler
Cooler Type: 420mm AIO Liquid Cooler | Dimensions (LxWxH): 457 × 137 × 53 mm | Fans: 3x 140mm Fans | Fan Speed: 1700 RPM | Noise Level: 33.8 dBA | Socket Support: LGA 1700, 1200, 1150, 1151, 1156, 2011, 2066, AM4, AM5, sTR4 | RGB: Yes
- Top-notch cooling performance
- LCD Screen
Be it high-performance SSDs or memory kits, Corsair has upheld an illustrious reputation in the era of modern-day gaming. Their efforts within the AIO cooling space are mainly highlighted through the iCUE series of coolers, which are known for their incredible cooling potential.
Cooling Performance: 420mm coolers are heralded for their beastly performance; however, the Corsair iCUE H170i Elite LCD XT takes that up a notch with its dense radiator and powerful AF140 Elite RGB fans. Speaking of which, the fans offer a maximum speed of 1700 while also peaking in at an airflow of 89 CFM. Following the trend of the robust configuration, Corsair has equipped it with a high-performance pump that boasts a flow rate of 0.82 L/minute.
Build Quality: Weighing in at a whopping 1.95 kilograms, the Corsair iCUE H170i Elite is undoubtedly a monolithic cooler, which is precisely why it has been backed up by a solid structure. It uses an aluminum construction for the radiator, low permeation rubber for the tubing, and a copper CPU plate. Instead of ML Elite fans, Corsair has made the AF Elite fans for this variant, which come with anti-vortex vanes, fluid dynamic bearings, as well as a total of 9 blades.
Aesthetics: The Corsair iCUE H170 Elite LCD XT is well-equipped when it comes to visually striking elements. Between clean-looking A-RGB on the fans all the way to the 480×480 LCD screen, the level of customizability the cooler offers is fantastic. That is further enhanced thanks to the clean black coating on the radiator, which blends well with all of the lighting on display.
Noise Level: As stated on the official spec sheet, the fan noise levels can range from 0 to 37 dBA depending on the workload, whereas the pump’s noise levels can reach 20 dBA when measured from a distance of 1 meter. During testing, the fans reached a maximum noise level of 53 dBA, which is reasonable, especially when accounting for the ambient noise output of 33 dBA.
Value For Money: While the Corsair iCUE H170i Elite LCD XT is a pricey option, that does not mar its value by any means. It is clear that its otherworldly performance, exceptional build quality, and the presence of an LCD screen have increased its overall cost; however, anyone interested in obtaining those attributes is bound to be pleased by any measure.
Buy It If:
You want the best possible performance: The Corsair iCUE H170i Elite LCD XT ranks among the most powerful 420mm coolers you can your hands on.
You want a functional LCD screen: Its position as an enthusiast-grade AIO CPU cooler means the presence of an LCD screen is anything but extraordinary.
Don’t Buy It If:
You are on a limited budget: Coming in at a premium price tag, the Corsair iCUE h170i Elite LCD XT will be out of the question for anyone working with a limited budget.
What Makes It The Best Performance 420mm AIO CPU Cooler?
The Corsair iCUE H170i Elite LCD XT comes with powerful fans, a zero RPM mode, and an LCD screen for added customizability. Above all, it provides unparalleled cooling performance, taking the spot as the Best Performance 420mm CPU Cooler.
Arctic Liquid Freezer II 420
Best Value 420mm AIO CPU Cooler
Cooler Type: 420mm AIO Liquid Cooler | Dimensions (LxWxH): 458 × 140 × 63 mm | Fans: 3x 140mm Fans | Fan Speed: 1700 RPM | Noise Level: – | Socket Support: LGA 1700, 1200, 115X, 2011-3, 2066, AM3(+), AM4, AM5 | RGB: No
- Phenomenal cooling performance
- Lower noise levels
- Enlarged radiator
- Fantastic Value
- VRM fan
- Plain looks
Arctic’s Liquid Freezer II series of AIO coolers are hailed as the best value AIO coolers in the market, and the 420 variant of the series is no exception to this.
Cooling Performance: Much like the previous iterations in the Liquid Freezer series, the 420mm does not disappoint in terms of cooling performance. The Liquid Freezer II 420 uses three of their 140mm P14 fans in conjunction with an enlarged 37mm Radiator for excellent heat dissipation. The P14 fans reach a maximum speed of 1700 RPM, which falls slightly behind the maximum operational speed of the pump, which stands at 2000 RPM.
Build Quality: The Liquid Arctic Freezer II 420 is rather well-built in all departments. It comes with fiber-reinforced tubing while also incorporating built-in cable management to hide any cables running through. In addition to that, Arctic’s in-house pump ensures a more efficient operation than its contemporaries while also consuming less power. Topping all of that off are the P14 fans that have been designed particularly for a high-pressure output of 2.4mm H2O.
Aesthetics: While aesthetics have not been completely disregarded with the Liquid Freezer II 420, it is clear that they were not the main priority. The cooler comes encapsulated in a matte-black coating, which extends all the way to the P14 fans. Similarly, the water block also does not have any RGB or LCD, although its size is fairly large due to the presence of an additional VRM fan. It is worth mentioning that separate variants of the cooler do come with A-RGB fans for a little extra.
Noise Level: Arctic seems to have placed an astounding amount of effort in maintaining lower noise levels. While the P14 fans are already reasonably silent even when operating at higher speeds, Arctic has gone out of its way to ensure that the in-house pump also remains quiet at all times. On the other hand, the VRM fan also manages to remain quiet, which is an impressive feat considering its smaller size.
Value For Money: The Arctic Liquid Freezer II 420 boasts unmatched value for money. It manages to match the higher-end AIO coolers in terms of performance, all the while costing significantly less. Additionally, Arctic has also added a VRM fan, which proves to be more than just a gimmick, managing to lower the VRM temperatures in most cases. Lastly, the cooler also remains vastly power efficient, which further adds to its already well-received price-to-performance ratio.
Buy It If:
Here are some of our shots when we tested the Arctic Liquid Freezer II – 420:
You need the best value possible: The Arctic Liquid Freezer II 420’s value supersedes that of any other 420mm cooler in the market, that too by a considerable margin.
Don’t Buy It If:
You need fancier aesthetics: The Arctic Liquid Freezer II 420 does not necessarily excel on the basis of visuals.
What Makes It The Best Value 420mm AIO CPU Cooler?
Not only does Arctic Liquid Freezer II 420’s performance benefit from the larger 37mm radiator, but it also blows every 420mm AIO out of the water when it comes to sheer value. Combine that with the addition of an integrated VRM fan, an efficient in-house pump, and high-performance P14 fans, and you get the Best Value 420mm AIO CPU Cooler.
More From Arctic:
Silverstone IceMyst 420
Best Looking 420mm AIO CPU Cooler
Cooler Type: 420mm AIO Liquid Cooler | Radiator Dimensions (LxWxH): 456 × 120 × 28 mm | Fans: 3x 140mm Fans | Fan Speed: 1750 RPM | Noise Level: 30.8 dBA | Socket Support: LGA 1700, 1200, 115X, 2011, 2066, AM4, AM5 | RGB: Yes
- Great performance
- Aesthetically pleasing design
- Stackable fans
- Average noise output
Silverstone’s IceMyst series of coolers is their take on well-constructed AIOs while accompanying distinct aesthetics and features that set them apart from the competition.
Cooling Performance: IceMyst has gone to extraordinary lengths to maximize the cooler’s performance. The 140mm fans it arrives with offer a maximum speed of 1750 RPM, with the pump also managing a respectable motor speed of 3100 RPM. Perhaps the biggest peculiarity the series brings is the ability to stack fans on top of the pump to cool down separate parts of the motherboard. Everything ranging from VRMs, SSDs, and RAM modules can be cooled down using these fans.
Build Quality: Build quality is not an aspect where the IceMyst 420 wavers. In fact, you get an aluminum radiator optimized specifically for higher pressures along with a convexed copper baseplate in order to maintain better contact with the CPU. While the pump doubles down as a mount for the stackable fans, its original functionality is also utilized through the three-phase, six-pole design in order to increase its overall reliability and efficiency.
Aesthetics: On an aesthetic level, the Silverstone IceMyst 420 outdoes most coolers it competes against. Not only is the design remarkably uncluttered, but Silverstone has managed to sneak in clean RGB elements on the pump as well as the fans. This is further evidenced by their clean cable management system, which allows you to synchronize RGB through a single header for all of the fans.
Noise Level: Noise levels for the Silverstone IceMyst 420 remain fairly low, with the fans only reaching a maximum output of 30.8 dBA. On the other hand, It is worth mentioning that adding extra fans to cool down other components will result in an inevitable increase in the overall sound, especially considering their maximum noise level of 28.2 dBA.
Value For Money: Despite the addition of new features, the Silverstone IceMyst 420 is modestly priced. The cooler presents you with an aesthetically appealing design, a reliable pump, and stackable fans that can be attached directly to the pump. Even barring the unorthodox pump design, the cooler offers plausible value for money just as a standard 420mm cooler, which is only further increased through the addition of these features.
Buy It If:
You are looking for a visually appealing 420mm cooler: From the silver finish on the pump to the neat RGB, the IceMyst 420’s design is certainly visually striking.
You intend to cool other components: Adding fans on top of the pump housing allows you to cool other components on the motherboard, which might be ideal for a motherboard that lacks onboard cooling.
Don’t Buy It If:
You want a silent experience: While the Silverstone ICeMyst 420 is reasonably quiet, its noise levels can be a problem for anyone who likes a quieter environment, especially if you add more fans to cool other components.
What Makes It The Best Looking 420mm AIO CPU Cooler?
Packed with an efficient motor consisting of a three-pole, six-phase design as well as great value, the Silverstone IceMyst 420 does not miss the mark when it comes to integral components. It also does not fall behind in terms of build quality, all the while incorporating the novelty of stack fans. All of that is topped off with the cooler’s sleek visual appearance, which gives it the title of the Best Looking 420mm CPU Cooler.
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- Thermalright Frozen Magic 360 Scenic V2 Liquid Cooler Review
Important CPU Cooler Key Terms
It is easy to be inundated by the number of technical terms usually thrown in by manufacturers. Here are brief definitions of a few CPU Cooler key terms for anyone unaware of technical terms within the space.
- TDP: The thermal design power of a CPU cooler is a direct measure of its overall cooling capacity, determining the amount of heat it can dissipate.
- Liquid Cooling: Use of a liquid coolant to dissipate heat from computer components, namely the CPU in the case of an AIO cooler.
- Radiator: A radiator’s job is to dissipate the heat flowing into it into the surroundings. This is done through a combination of metal fins and fans.
- Pump: The pump serves the purpose of transferring the liquid to the radiator, where the heat can be dissipated.
- Thermal Paste: Thermal compound is a conductive material used to eliminate gaps between two surfaces and improve heat transfer.
- Noise Level: As suggested by the name, the noise output refers to the amount of noise generated from your AIO liquid cooler.
How We Selected The Best 420mm AIO CPU Coolers
There are a lot of factors you need to account for when selecting a CPU cooler. Here are a few factors I took into consideration when selecting the Best 420mm AIO CPU Coolers.
Cooling performance is undoubtedly the most crucial aspect of a CPU cooler. Of course, the kind of performance you require will depend on the processor you are using. To put into perspective, a flagship processor will require a top-of-the-line cooler, especially if you intend on overclocking it. Components affecting AIO coolers’ cooling performance include the fans, radiator, and pump. Every cooler featured on my list performs well, facing no issues accommodating high-end processors.
A significant concern for triple-fan radiators can be the loud noise generated by the constant operation of the fans and the pump. In order to avoid this, you’ll need a cooler that remains quiet even under load. Thankfully, my list features several AIO CPU coolers that remain silent.
A well-built cooler is the key to a sustainable computer system, which is precisely why you must opt for a cooler that does not compromise on its build quality. Ideally, an AIO cooler should consist of a well-constructed radiator, an efficient pump, as well as a solid fan that provides heat dissipation.
While aesthetics might not be the main concern for some, anyone interested in enhancing the look of their setup will need to purchase a cooler that matches the overall theme of the build. For instance, a white PC build will require a white cooler to match the rest of the system.
Value For Money
Lastly, one must carefully analyze the value for money a cooler offers. This can be done by simply evaluating the price-and-performance ratio while also weighing in other aspects, including features, aesthetics, and sound, in contrast to its price. I made sure to cover every inch of detail, making it easier for readers to gauge the actual value a cooler offers.
Why You Should Trust Us
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Since its inception, Tech4Gamers has continued to evolve within the gaming landscape, with their feats also being recognized by esteemed manufacturers, including Noctua, Corsair, and Thermaltake.
Frequently Asked Questions
Yes, a 420mm AIO mostly performs better than a 360mm one.
Yes, 420mm is certainly overkill for anyone who does not require the best cooling possible.
The AIO size can be a determining factor of the cooler performance your cooler provides.
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[CPU Coolers & RAM Expert]
Hayyan Serwer is a tech enthusiast, with a love for PC building and article writing. Hayyan specializes in writing about CPU coolers and RAM kits. Hayyan has been familiar with the tech industry for over half a decade now, and has now stepped into providing quality reviews for the latest and greatest tech.