While all coolers for computer parts like CPUs and GPUs generally involve a heatsink and some fans to cool that heatsink off, the best, highest-end coolers are water or liquid coolers. You see water cooling solutions all the time in premium PCs built by OEMs and individuals alike, and they usually perform better than regular air coolers. But there is more to water cooling just being better than air cooling (which isn't always true), and it's not for everyone.
The basics of water cooling
Computer parts generally make heat when they operate, and some of them (mainly CPUs and GPUs, but there are PSUs and SSDs with liquid cooling) make enough heat to warrant a dedicated cooling device. In order to siphon the heat off of these components, you need to coax it into a big mass of metal called a heatsink and then cool that heatsink down. While you can just have a heatsink sit and let air alone take care of the job, most coolers use a fan to get a heatsink to cool down as fast as possible.
The whole point of water coolers is to use water or other liquids to get the heat from the chip to the heatsink. Every water cooler pumps water through a loop with three key components: a pump that may also be connected to a reservoir full of water or cooling liquid, a coldplate pressed up against the chip to siphon heat away, and the radiator or heatsink where all that hot water heats up metal fins that fans can cool down. All the water in the loop is continuously moving through these three components over and over.
But why use water for cooling? Well, water is great at holding heat and only boils at 100 degrees Celsius, which is quite hot. Additionally, it's possible to hook up a CPU and GPU to the same water cooling system, which can be desirable for some users and simply isn't really doable in a desirable way with air coolers.
Water cooling vs air cooling: Which is better?
While water cooling is generally a higher-performance solution for cooling, it's not necessarily true that the best coolers for CPUs or GPUs are liquid. In fact, you'll find that most coolers that we recommend are air coolers, and there are many good reasons why that's the case.
First, let's talk about performance. While the highest-end liquid coolers with 280mm, 360mm, and 420mm radiators will outperform even the largest air coolers, that's not true for coolers with 120mm, 140mm, and 240mm radiators. These smaller radiators will be matched and outperformed by air coolers, and 120mm and 140mm radiators especially perform poorly among water coolers.
Size is also an important consideration. While liquid coolers generally take up less space than higher-end air coolers, not all cases support all radiator sizes. Radiators are long rather than large overall, so you'll find many mid-tower cases only support 240mm or 280mm radiators rather than higher-end 360mm radiators but still have room for the largest air coolers. At the other end of the spectrum, the smallest air coolers are way smaller than the smallest water coolers, and they're generally better for cramped cases.
Water cooling is best for PCs where you need lots of cooling for high-powered consumption components and where there's a good amount of room for radiators but not air coolers.
Finally, when it comes to price and value, air coolers have water coolers beat. Great budget CPU coolers like Thermalright's Peerless Assassin 120 SE can go toe-to-toe with the best 240mm and 280mm water coolers for around half the price or less and are really only bested by coolers with larger radiators. Water coolers can be pretty cheap, it's just that they often won't be very good compared to similarly priced air coolers.
Thermalright Peerless Assassin 120 SE CPU Cooler
Thermalright's Peerless Assassin 120 SE is a value-oriented CPU cooler that costs around $40 and offers six heatpipes and two 120mm fans.
Even Noctua's NH-D15, which performs about the same as the Peerless Assassin and costs over twice as much, still has competitive performance compared to most liquid coolers in its price bracket.
Noctua NH-D15
The Noctua NH-D15 is one of the most powerful air coolers on the market. It can handle high-performance CPUs, and while it's large, it gets the job done. Oh, and it comes in a stunning brown color.
That said, water cooling is best for PCs where you need lots of cooling for high-powered consumption components and where there's a good amount of room for radiators but not air coolers. The first case is obvious, but you may not have thought about the second. Lots of ITX chasses and prebuilt PCs are actually shaped specifically for liquid cooling, like Corsair's 2000D Airflow and NZXT's H1.
The pros and cons of custom water cooling
When it comes to water cooling, you have two options: all-in-one (or AIO) liquid coolers and custom-built liquid coolers. By far, AIOs are more popular than custom solutions since building your own liquid cooling setup requires more skill, time, and, of course, money. There's nothing you really need to do to set up an AIO cooler other than installing it just like any cooler. They're also still affordable and can output high performance. Arctic's Liquid Freezer II series is a particularly potent liquid cooler, including even the 240mm radiator variant.
Arctic Liquid Freezer II 360
The Arctic Liquid Freezer II 360 is a 360mm AIO liquid cooler for high-end CPUs, but it also comes in a few different sizes to suit your chassis.
Corsair's iCUE H710i Elite LCD XT, on the other hand, is a more premium, flashier AIO that performs similarly.
Corsair iCUE H170i Elite LCD XT
Bigger usually means better, which is why the Corsair iCUE H170i Elite LCD XT takes our spot for the best-performing AIO cooler from Corsair. It has a 420mm radiator with three 140mm fans for excellent thermal performance.
However, custom cooling does have its advantages:
- Better performance thanks to higher-quality parts
- More personalization for visuals, like being able to dye the cooling liquid
- Being able to put the CPU and GPU in a single loop
- Better GPU cooling options since most AIOs are just for CPUs, and very few GPUs come with an AIO liquid cooler
Companies like EK offer custom water cooling kits that contain all the parts you'd need for a basic custom loop, which makes the building process more accessible but not exactly easy. Compatibility is also a key thing to look out for because all the tubes, fittings, and waterblocks (the cooling parts that go directly on top of the CPU and GPU) need to be the right size, and the waterblocks also need to be compatible with the chips they're being installed on.
You also need to do maintenance on custom cooling solutions, which involves making sure there aren't any leaks anywhere and draining the liquid from time to time for cleaning/ Of course, you are getting lots of benefits by going for custom water cooling, but it's really only worth it for true enthusiasts and hobbyists.
Water cooling is great for high-end and specialized PCs but loses to air cooling for lower-end builds
While the best CPUs and best GPUs (especially GPUs) do really well under air coolers, you can really take things to the next level with water coolers if you can justify the money it'll cost. For high-end CPUs like the Core i9-13900K, water cooling is practically required for the best performance, but every other CPU runs fine on air cooling, and top-end GPUs already come with great coolers themselves.
The place for water cooling is really in high-end PCs, compact PCs that are designed for large radiators, and PCs that you really want to make your own. If you don't really need any of that, you'll be happy with an air cooler, but if you want one or more of those three things, water cooling is definitely the way to go.