The best liquid cooler is the perfect choice for keeping your expensive, lovingly overclocked processor alive. Sure a standard air-cooler will get the job done, but if you want to keep things cheery and chilled throughout your CPU’s life then a good all-in-one (AIO) cooler is the way to go.

The top cooling manufacturers have been put through their pace on our test bench, with AIO liquid CPU coolers from AlphaCool, Thermaltake, NZXT, Arctic, and of course Corsair. But why do you need to go all out on a liquid 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 water and electronics go together like chalk and a particularly soggy cheese, 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.

And 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, taking in GPU cooling while you’re at it, but that’s far more in-depth and a serious build project in its own right.

Where to begin: Here’s how to overclock your CPU or GPU

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

The best liquid coolers are:

AlphaCool Eisbaer 240
Corsair H100i Pro RGB
Thermaltake 240 Water 3.0
Corsair H115i Pro
NZXT Kraken X62
Arctic Liquid Freezer 240


WINNER: BEST LIQUID COOLER

ALPHACOOL EISBAER 240
Approx. $145 | £131

Pros
Tick Great thermal performance
Tick Cheap
Tick Refillable and expandable

Cons
Cross Installation can be tricky

AlphaCool has really outdone itself with the Eisbaer 240. This cooler came out on top of our cooling charts, and it’s cheap to boot. AlphaCool also keeps things standard with its ¼ inch connectors and refillable loop, adding even more lifespan and potential for upgrading down the road.

In ditching the software for this not-so-closed-loop cooler, AlphaCool has made it so that this capable chiller runs straight from your BIOS. It’s not the flashiest of all the chip-chillers, and unfortunately there’s no RGB lighting if you are into that sort of thing, but with a nearly all-black design, sleeved fan cables, and a semi-industrial look, this cooler blends in with your rig and gets on with the job at hand.

RUNNER-UP

CORSAIR H100I PRO RGB
Approx. $110 | £103

Pros
Tick Near-silent
Tick Maglev fans
Tick Good software

Cons
Cross RGB lighting can be hit-or-miss

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 more svelte design of the radiator either. No, the real boon of the new H100i Pro RGB is the noise it makes… or rather the lack thereof.

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 much 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 games, ones that are more GPU and less CPU dependent, you may not hear the fans at all.

RUNNER-UP

THERMALTAKE 240 WATER 3.0
Approx. $114 | £111

Pros
Tick RGB-palooza
Tick Simple hardware controller
Tick Quiet

Cons
Cross Not the greatest performance

Thermaltake’s Water 3.0 is the slightly more budget-friendly version of its Premium Floe Riing 240 cooler. It ditches the RGB pump lighting and the app support, thankfully, but still delivers low-noise performance with a little more flash. The fan controller in the box controls fan lighting profiles, but it also allows for either low-noise mode or normal mode for performance.

At stock speeds, this cooler is more than capable, and as one of the cheapest options it’s a great buy for someone that wants a quiet liquid-cooled build. This cooler is capable with some mild clockspeed tuning, but for anything a little more intensive, you might want to look elsewhere.

WINNER: BEST LARGE LIQUID COOLER

CORSAIR H115I PRO
Approx. $130 | £115

Pros
Tick Maglev fans
Tick Near-silent operation
Tick Capable for overclocking

Cons
Cross Pricey

The Corsair H115i Pro RGB offers good performance with incredibly low noise. The two ML-Series 140mm fans combine the low-RPM performance of the larger blade size with the low-friction operation, thanks to the magnetic levitation design. This combination is conducive to the fantastic airflow these fans produce with little noise whatsoever.

With Corsair at the helm, and RGB in the name, it’s easy to guess that this cooler comes fitted with a handful of rainbow LEDs to light up your rig. Surprisingly, these little luminous electrodes never made it into the fans, although that is likely good news for your bank account. Corsair’s H115i Pro is a welcome addition to any silence-focused build – mostly because you’d barely know it was there if it wasn’t for the considerably chilly CPU temps.

RUNNER-UP

NZXT KRAKEN X62
Approx. $133 | £140

Pros
Tick Stunning design
Tick Great performance

Cons
Cross The CAM app needs work
Cross …lots of work

NZXT loves to make its products stand out from the crowd, and the Kraken X62 is no different. This chunky 280mm cooler features a unique infinity mirror lighting design that makes the Kraken x62 an incredible build centrepiece.


Overall, this is the most stunning-looking cooler of the lot. NZXT has a certain flair for lavish designs, and you won’t find many other coolers that draw the eye away from a flashy graphics card as much as the Kraken x62. Unfortunately, NZXT couldn’t carry this level of detail over to its CAM app, which left this chiller with mediocre performance. If you aren’t scared of kicking fan control back to BIOS, then it should be, at least, a quieter unit.

WINNER: BEST CHEAP LIQUID COOLER
ARCTIC LIQUID FREEZER 240
Approx. $85 | £78

Pros
Tick Cheap
Tick Great performance
Tick Four fans included

Cons
Cross A little ugly

Arctic is offering the cheapest chiller we’ve looked at by far. But Arctic is one of the few manufacturers to include enough fans in the box to set up a full push/pull configuration right out of the box. Thanks to these extra fans spinning away in your rig, this cooler offers great cooling potential and value for money, and was almost our pick as the best liquid cooler overall.

With price/performance metrics off the charts, it’s really no surprise the Liquid Freezer was a close second for the top spot. No it’s far from the prettiest design in the world, and Arctic have ditched all the RGB flair, but in return you get a cooler that gets the job done – with no unnecessary features, and no frustrating software. Kudos, Arctic.

Sure, going to the extreme effort of adding a full water cooling loop to your gaming rig will give you the best combination of performance and pretties, but it takes a hell of a lot of work. And if you’re not building a showpiece machine, or a super-overclocker, then chances are you just want something simple to chill your chips with.

And that’s the beauty of the all-in-one liquid cooler. The AlphaCool Eisbaer is our current favourite, offering the option to widen out the closed loop thanks to its standard 1/4-inch connectors and refillable reservoir. It’s also not too pricey either.

But Corsair’s range delivers some excellent liquid coolers too, with the Pro RGB Pro able to run in a completely silent, passive mode, and the 280mm version offering great chip-chilling performance.

Then at the more budget end of the market, the Arctic Liquid Freezer is the cheapest kit, yet still comes with four fans to enable a push-pull setup for extra cooling. Now there’s no excuse not to liquid chill your chips.