Best AIO cooler – the top liquid coolers for your CPU in 2021

Want to water cool your gaming PC? We've tested the best liquid CPU coolers from MSI, NZXT, Corsair, and Cooler Master to find out which is worth your money

The best AIO cooler sits atop a CPU inside a gaming PC

The best AIO cooler is one that should make the perfect combination with some of the best gaming CPUs. Despite increases in performance-to-TDP ratios, processors can still get mighty hot these days – especially if you overclock them. If you’ve learnt how to overclock your CPU and want to put these skills to the test, you might have an easier time of it using one of the best liquid coolers over an air cooler. As more and more graphically intensive titles like Metro Exodus are released, overclocking might become more common. A good AIO cooler lets you overclock to crank out more performance with less risk of melting your CPU to a crisp.

The top cooling manufacturers have been put to the test on our test bench, with all-in-one (AIO) liquid CPU coolers from MSI, Cooler Master, NZXT, and Corsair. But why do you need to go all out on a CPU cooler? If you want to push your processor’s clock speeds to meet its potential then you need to make sure overheating isn’t a factor, and that’s where liquid coolers come in.

You might think liquids shouldn’t mix with electronics, yet an effective pump and radiator combo will move heat away from that CPU faster than you can say ‘thermal throttling’. Of course, they often feature more RGB LEDs than you can shake a stick at, so you need not worry about colour-matching with the rest of your rig.

All-in-one liquid coolers take all the pain out of putting the soggy stuff inside your PC. You can create your own custom loops, letting you keep the best graphics card running cool too, but that’s far more in-depth and a serious build project in its own right.

AIO coolers, however, can be set up in half an hour and still make a tangible difference to your gaming PC.

Here are the best AIO coolers:

  • MSI MEG CoreLiquid S360
  • NZXT Kraken X63
  • NZXT Kraken M22
  • Corsair H100i Pro RGB
  • Cooler Master MasterLiquid ML360R
  • Cooler Master MasterLiquid ML240L
Check prices on Scan

MSI MEG CoreLiquid S360

The best AIO cooler is the MSI MEG CoreLiquid S360.

The MEG CoreLiquid S360 isn’t MSI’s first AIO cooler, but it’s certainly the best for three reasons: cooling, compatibility, and the extra considerations it makes. Not only does it balance impeccable performance with a low noise output even when the Silent Gale P12 fans spin at 2,000RPM, it supports Intel’s latest Alder Lake series of CPUs with an LGA1700 bracket right out of the box. It even packs a 60mm fan in the pump to make sure the motherboard’s VRMs remain cool – something that’s often overlooked by other AIO options.

MSI’s pièce de résistance is the built-in screen, which isn’t a new concept but none do it better than MSI’s MEG CoreLiquid S360. Alongside the usual images, GIFs, and system information others can display, this 2.4-inch IPS display does what most of its competitors can’t: play .mp4 files. You won’t need to tilt your head wherever you pop the radiator in your case, too, as the block twists 90 degrees so it’s always the right way up.

If money’s no object, no other AIO cooler hits all the same heights as the MSI MEG CoreLiquid S360.

What we like…
Tick The best IPS screen
Tick Supports the latest sockets
Tick As quiet as a mouse

MSI MEG CoreLiquid S360 specs
Size 360mm
Fans 3x PWM 120mm
Compatibility Up to AM4, LGA 1700, TR4
check prices on Amazon

nzxt kraken x63

The best value AIO cooler is the NZXT Kraken X63.

This 280mm liquid cooler from NZXT is our pick if you’re looking for a seriously good all-rounder. The virtually silent fans on the radiator have fluid-dynamic bearings, giving them a longer lifespan and quieter operation than any other fan technology. Naturally, there’s customisable RGB lighting on the pump cover so people know you’re not running any old stock solution.

With the X63 you’ll see idle and load temps in another league to air coolers. If you are overclocking, just make sure you’re picking up one of the best gaming motherboards to match.

What we like…
Tick Great thermal performance
Tick Affordable
Tick Near silent fans

NZXT Kraken X63 specs
Size 280mm
Fans 2x PWM 140mm
Compatibility AM4, LGA 1151, LGA 2011-3
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nzxt kraken m22

The best 120mm AIO cooler is the NZXT Kraken M22.

It’s true that the bigger the radiator, the better the job an AIO cooler can do, but sometimes you just don’t have the space for one. This doesn’t mean you should sacrifice the chilling effects a liquid cooler offers, however, as there are smaller options to choose from that might be easier to shimmy into your case, still offering cooling a cut above the best CPU coolers.

The NZXT Kraken M22 is the little brother to our favourite AIO cooler and comes with many of the same perks. It keeps things quiet, goes easy on your wallet, and keeps your CPU at the right temperature for gaming, but best of all, it could be considered the most compatible AIO cooler you’ll find with its small form factor and support for all modern Intel and AMD CPUs.

What we like…
Tick Compact
Tick Wide range of compatibility
Tick Quiet fans

NZXT Kraken M22 specs
Size 120mm
Fans 1x PWM 120mm
Compatibility AM4, LGA 1151, LGA 2033, LGA 2066
Check prices on Amazon

Corsair H100i Pro RGB

The quietest AIO cooler is the Corsair H100i Pro RGB.

The latest update to the classic Corsair H100i liquid CPU cooler isn’t just about that new ring of LED light around the shrunken pump. It’s not even about the slicker radiator design, either. No, the best thing about the new H100i Pro RGB is the noise it makes… or rather the lack of noise, making it perfect for a near silent gaming PC build.

Thanks to the super-quiet maglev fans included in the package, and the addition of a Zero RPM mode, the Pro RGB can stay almost entirely silent for most of the time your PC’s online. Relying on the flow of water and the passive cooling of the radiator alone, the H100i can keep the CPU cool enough not to have to worry the fans until you start to really thrash it. That means in a lot of the best PC games, ones that are more GPU and less CPU dependent, you may not hear the fans at all.

What we like…
Tick Near-silent
Tick Maglev fans
Tick Good software

Corsair H100i Pro RGB specs
Size 240mm
Fans 2x PWM 120mm maglev
Compatibility AM4, LGA 1151, LGA 2011-3

Read the PCGamesN Corsair H100i Pro RGB review for our full verdict and score.

check prices on Amazon

cooler master masterliquid ml360r

The best RGB AIO cooler is the Cooler Master MasterLiquid ML360R.

There’s no reason you can’t be serious about your cooling and want to add a splash of colour to your gaming PC in the process – after all, the best gaming keyboards and best gaming headsets all have RGB nowadays, so why shouldn’t your CPU cooler match?

Cooler Master’s MasterLiquid series does this beautifully with its bright CPU block, and it comes in a handful of different sizes to make your next CPU upgrade a bit easier. The MasterLiquid ML360R has plenty of sufrace area and three 120mm fans to dissipate heat across its large radiator.

What we like…
Tick Colourful RGB
Tick Three fans!
Tick Remains affordable

Cooler Master MasterLiquid ML360R specs
Size 360mm
Fans 3x PWM 120mm w/ RGB
Compatibility AM4, LGA 1151, LGA 2033, LGA 2066
check prices on Amazon

Cooler Master MasterLiquid ML240L

The best cheap AIO cooler is the Cooler Master MasterLiquid ML240L.

If you’re looking for a cost-effective AIO cooler that still looks brilliant in your windowed case, then this 240mm liquid cooler from Cooler Master is a great option. There’s customisable RGB lighting on both the fans and the pump cover.

Even at this price point, it’s still better than pretty much any air cooler you’re going to find – plus, it still looks cool, right?

What we like…
Tick That low price
Tick RGB everywhere
Tick Two 140mm fans

Cooler Master MasterLiquid ML240L Specs
Size 240mm
Fans 2x PWM 120mm w/ RGB
Compatibility AM4, LGA 1151, LGA 2033, LGA 2066

Is an AIO cooler better than an air cooler?

Everyone that builds or upgrades their own PC will face at some point face the question whether to go for an air cooler or water cooler. Both have gotten much better over the past decade that there’s no clear winner.

AIO coolers have improved to the point that, while still possible, leaks aren’t something you’ll need to worry about. Air coolers, on the other hand, can now keep up with liquid cooling temperatures. It’s a similar stalemate in terms of noise, as the amount of high pressure fans attached to the radiator could be compared to the fans on an air cooler, but this will vary per model. AIO coolers maintain the edge with how quickly they return to idle temperatures, but otherwise both are suitable to cool your PC.

Do AIO coolers work with any CPU?

The short answer is no, you’ll need to check that an AIO cooler’s socket support matches your CPU before purchasing one. Intel’s 12th generation Alder Lake processors, for example, run on an LGA 1700 socket, which isn’t the same as the 11th generation’s LGA 1200, and the same goes for AMD as new processors come out.

The good news is that most manufacturers update models to keep up with the latest and greatest, and sometimes even offer brackets sold separately so you can easily upgrade without having to buy a new one.

Best AIO cooler deals

If our top picks don’t cut it, here are some of the best AIO cooler deals that are as cool with your bank account as they are with your gaming PC:

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