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The best AIO coolers for 2021

For decades, PC enthusiasts have been looking to liquid cooling to maximize performance while minimizing noise. The reason is simple: Liquid can typically move heat away from the CPU faster than air, requiring less work from the fans, which generates less noise. Like any enthusiast technique, though, liquid cooling had a high barrier to entry for years, with various components and the omnipresent risk of leaking. That risk is still present, but all-in-one (AIO) liquid coolers can ease newcomers along. If you don’t want to shop for fittings or bend hardline tubing yourself, the best AIO coolers can make installing a water-cooling loop far easier.

Before diving in, it’s worth pointing out that all these coolers are available in various sizes. We split up our picks into different sizes, but to give you a few more options, we didn’t repeat the same cooler in a different size. If you’re eyeing the Arctic Liquid Freezer II 360, for example, the 240mm variant is still an option. It’s priced reasonably for the being the best AIO cooler.

The best 360mm AIO: Arctic Liquid Freezer II 360

arctic liquid freezer ii 360 all in one liquid cpu cooler
Socket compatibility Intel: LGA1151, LGA1150, LGA1555, LGA1156, LGA2011-3, LGA2066
AMD: AM4
Dimensions (length by width by height) 398mm by 120mm by 38mm
Included fans Three Arctic 120mm fans
Fan speed 200 to 1,800 RPM

When it comes to raw thermal performance, the Arctic Liquid Freezer II is the best AIO cooler on the market. It reaches a similar performance to competing coolers at NZXT and Corsair while being very inexpensive. The 360mm option is only $125, while the NZXT Kraken X73 — another 360mm AIO — clocks in at nearly $200. The price is even more impressive when you consider the cooler’s features. In particular, the pump is controlled by PWM, allowing it to modulate with the workload rather than run at full speed all the time.

The Liquid Freezer II also includes a 40mm fan next to the pump, set to sit over your motherboard’s VRM chips. In more extreme overclocking sessions, this may improve stability.

This cooler is all about performance and price. It gets those two bits right, but not without some concessions. It doesn’t feature any sort of lighting, and the design may not be to everyone’s tastes.

Still, the Arctic Liquid Freezer II hits a sweet spot that other coolers can’t compete with. Socket support is a little limited, but the Liquid Freezer still supports most recent chips. On AMD, it supports AM4 CPUs, and on Intel, it supports all LGA115x sockets, as well as 2011-3 and 2066 with a square Independent Loading Mechanism (ILM).

The best 240mm AIO: NZXT Kraken X53

nzxt kraken x53 all in one liquid cooler
Socket compatibility Intel: LGA1200, LGA1151, LGA1150, LGA1155, LGA1156, LGA1366, LGA2011, LGA2011-3, LGA2066
AMD: AM4, TR4, sTRX4
Radiator dimensions (length by width by height) 230mm by 123mm by 30mm
Included fans Two Aer P120 120mm fans
Fan speed  500 to 2,000 RPM

Although significantly more expensive than the Liquid Freezer II, NZXT’s third generation of Kraken X coolers are worth their asking price. The design is much more appealing than Arctic’s offering while achieving similar levels of thermal performance. For looks, the Kraken X’s infinity mirror pump cap is a showstopper. It bounces light around inside the cap to create the illusion of infinite LED rings. Like nearly all NZXT products, the Kraken X53 is fully integrated with CAM, allowing you to monitor temperatures and tweak your lighting settings. Over the X52, the X53 also includes a NZXT Hue 2 connection on the pump, offering power for up to six Hue 2 accessories.

Unsurprisingly, socket support is excellent, with support for TR4 and AM4 on AMD, and LGA115X, 20XX, and 1200 on Intel. NZXT rates the Kraken X53 for six years of continuous use — 60,000 hours, technically — which is around what we’d expect for most AIO coolers. NZXT offers a six-year warranty, though, so you’re covered from any defects for the rated life of the cooler.

The best 120mm AIO: Corsair H80i v2

Socket compatibility Intel: LGA1200, LGA1150, LGA1151, LGA1155, LGA1156, LGA1366, LGA2011, LGA2066
AMD: AM4 (requires CW-8960046 bracket), AM3, AM2
Radiator dimensions (length by width by height) 154mm by 123mm by 49mm
Included fans Two Corsair SP120L 120mm fans
Fan speed 2,435 RPM

Finding a decent 120mm AIO cooler is tricky. Without proper surface area on the radiator, most 120mm coolers just aren’t up to snuff when it comes to cooling power. The Corsair H80i v2 solves that problem. The radiator is twice as thick, clocking in at 49mm compared to the standard 25mm. The H80i v2 doesn’t match the cooling performance of a 240mm radiator, but it gets a lot closer than a standard 120mm one. To get through the extra thick radiator, Corsair includes two SP120L PWM fans, so it’s easy to set up a push-pull configuration, but you’ll need to factor in the extra thickness of such a configuration when mounting.

As for support, the Corsair H80i v2 comes with Intel mounting hardware for socket 1366 up to LGA1200 (Intel’s redesign of LGA1151, designed for Comet Lake CPUs). Basically, if you have an Intel processor introduced after 2008, you’re fine. AMD support is a little sparser. The cooler technically supports AM2 up to AM4, but the box only ships with mounting hardware for up to AM3. You’ll need a separate AM4 bracket. Thankfully, Corsair sells them for only a few dollars. There’s no RGB on this one, either, though you can control fan speed and monitor temperatures through Corsair’s iCue software.

The best budget AIO: Cooler Master MasterLiquid ML240L v2

cooler master masterliquid ml240l v2 all in one liquid cpu cooler
Socket compatibility Intel: LGA1200, LGA1151, LGA1150, LGA1155, LGA1156, LGA2066, LGA2011-3, LGA2011
AMD: Am4, Am3+, AM3, AM2+, AM2, FM2+, FM2, FM1
Dimensions (length by width by height) 157mm by 119.6mm by 27.2mm
Included fans Two Sickleflow 120RGB 120mm fans
Fan speed 650 to 1,800 RPM

Cooler Master offers a range of “lite” AIOs, which are basically previous iterations of Cooler Master’s MasterLiquid line with increased socket support and double FEP tubing. At around $80, it’s hard to complain about the ML240L v2. It comes with a 240mm radiator, two RGB fans, and a small RGB controller. Thermal performance isn’t great, and the noise level is higher than some more costly options. However, the ML240L clocks in around $50 cheaper than most competing 240mm AIOs. Plus, you can always swap the fans out later for more lighting options and slightly better noise levels.

The Cooler Master ML240L comes with nearly universal socket support, too. On Intel, it supports LGA1200, LGA20xx, LGA115x, and LGA1366, and on AMD, it supports AM2 to AM4, as well as FM2 and FM1. For the price, it’s hard to beat the ML240L. If you can spend a little more money, though, you should. There are a lot of potential failure points in an AIO cooler, and cheaper coolers generally run a higher risk.

The best RGB AIO: EK-AIO 240 D-RGB

EK-AIO 240 D-RGB all in one liquid cpu cooler
Socket compatibility Intel: LGA1200, LGA1150, LGA1151, LGA1155, LGA1156, LGA2011, LGA2011-3, LGA2066
AMD: AM4
Dimensions (length by width by height) 275mm by 120mm by 27mm
Included fans Two EK-Vardar S 120ER D-RGB 120mm fans
Fan speed 550 to 2,200 RPM

There are a lot of AIOs with an RGB ring around the pump and even more with RGB fans. The EK-AIO 240 D-RGB goes off the deep end. Short of a small black strip where the tubes connect, the mounting block has a translucent, slightly diffused surface, washing out the lights inside into a beautiful display of color. EK is the place for custom water cooling, and the EK-AIO 240 shows why. When it comes to raw thermal performance, EK beats the Corsairs and NZXTs of the world. It includes two EK-Vardar S fans that run from 550RPM to 2,200RPM and includes support for Asus Aura Sync, Gigabyte RGB Fusion, MSI Mystic Light, and ASRock RGB Sync for the fans and pump.

The EK-AIO 240 is a better option due to the fact that it’s inexpensive. Cheaper than the 240mm counterpart at NZXT, and the same price as Corsair’s ever-popular H100i, this is a solid piece of equipment to meet your needs. Like a lot of the other options on this list, it’s available in 120mm and 360mm variants, too. On Intel, the EK-AIO 240 supports LGA115x and LGA20xx, as well as LGA1200. On AMD, it just includes an AM4 bracket. You can control the fans directly through your motherboard, but if you’re short on spots, you can pick up an EK-Loop Connect controller for another six PWM connections.

The best premium AIO: NZXT Kraken Z63

Socket compatibility Intel: LGA1200, LGA1150, LGA1151, LGA1155, LGA1156, LGA2011, LGA2011-3, LGA2066, LGA1366
AMD: AM4, sTRX4, TR4
Dimensions (length by width by height) 275mm by 120mm by 27mm
Included fans Two Aer P120 120mm fans
Fan speed 500 to 2,000 RPM

The NZXT Kraken Z63 is unnecessary, but that’s the point. It’s basically the Kraken X53, just with a larger radiator and a useful LCD display on the pump. It may seem a little gimmicky, but the display allows you to quickly see critical metrics from NZXT’s CAM software, including your fan speed and temperature. If you don’t want to monitor anything, you can throw a GIF on the display for the 2021 equivalent of putting an action figure in your PC.

The Z63 comes with a 280mm radiator, but NZXT offers 240mm and 360mm variations, too. Like the Kraken X53, the Z63 comes with two 140mm Aer P fans, and it supports most modern sockets. That includes TR4 for Threadripper, though you’ll need to pick up a separate Threadripper mounting bracket from NZXT.

A big part of the NZXT Kraken Z63‘s high price is the LCD display, but if you’re in the market for a premium cooler with flare to match, there isn’t a better option.

Frequently asked questions

What should you look for in an AIO cooler?

The most important part of an AIO cooler is the radiator size. A larger radiator offers better cooling performance, but you need to make sure it can fit inside your case. Otherwise, look at the socket support to make sure you can use the cooler with your motherboard and buy from a reputable brand.

How reliable are RGB AIO coolers?

Most AIO coolers have a lifespan of six years, regardless of if they have RGB or not. You can expect an AIO cooler from a reputable brand to run for six years without issues, but every cooler is a little different. We recommend looking up individual AIO cooler reviews to see if others have had issues with reliability.

What should you know before you buy an AIO cooler?

Before buying an AIO cooler, you need to know about the risks it may pose to your PC. Although failures are few and far between, every AIO cooler is still putting water dangerously close to your precious PC components, so there’s always a risk that the cooler could leak or fail and damage your parts. The fact that AIO coolers are closed makes matters worse because you can’t open the loop to see if there are any problems.

The best way to mitigate risk is to keep an eye on your cooler to see if there are any signs of leaking, and to monitor your CPU temperature to see if the pump is failing. As long as you keep an eye on both, you can find most problems before they do any catastrophic damage.

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