How to Buy the Right CPU Cooler: A Guide for 2021

One of the most important decisions when building your PC, especially if you plan on overclocking, is choosing the best CPU cooler. The cooler is often a limiting factor to your overclocking potential, especially under sustained loads. Your cooler choice can also make a substantial difference in noise output. So buying a cooler that can handle your best CPU’s thermal output/heat, (be it at stock settings or when overclocked) is critical to avoiding throttling and achieving your system’s full potential, while keeping the whole system quiet.

If you already have an idea of what you're looking for, check out our tested list of the Best CPU Coolers. If not, we’ll help you identify what type of cooler you need for your desktop PC, depending on your CPU and the things you do with it. Are you a heavy overclocker or do you prefer silent operation (or both)? Do you like a plain appearance or lots of RGB lights?

CPU Coolers come in dozens of shapes and sizes, but most fall into one of three primary categories: air, closed-loop or all-in one (AIO) coolers, or custom / open-loop cooling setups. Note that open-loop coolers are by far the most complex and expensive choice, though they can deliver unparalleled cooling results and unsurpassed looks. For a prime example of what can be achieved with a custom loop, see our Mirror Maze build, with its clear coolant and many mirrored surfaces. 

Those looking to build an open-loop setup for the first time may want to check out Corsair's HydroX lineup. It simplifies the process by walking you through selecting the right parts for your case, and provides video tutorials to ease installation. Don't expect a HydroX setup to be anywhere near as affordable as a closed-loop or air cooler, however. Custom cooling setups are expensive, no matter whose parts you buy.

Air coolers, made of some combination of metal heatsinks and fans, come in all shapes and sizes and varying thermal dissipation capacities (sometimes listed as TDP). High-end air coolers these days rival many all-in-one (AIO) liquid coolers that have become popular in the market over the past several years.

AIO or closed-loop coolers can be (but aren’t always) quieter than air coolers, without requiring the complications of cutting and fitting custom tubes and maintaining coolant levels after setup. AIOs have also become increasingly resistant to leaks over the years, and are easier to install. But they require room for a radiator, so may require a larger case than some air coolers.

If a high-end air cooler or AIO isn’t sufficient for the clock speeds you’re trying to achieve, the next step would be to go for a fully custom cooling loop with larger radiators able to remove even more heat from the system. In general, the larger the radiator on the AIO or custom-loop cooler, the better it will perform (although things like flow rate and fin density also come into play). But if you aren't aiming for the best possible overclocks with a powerful high-end desktop (HEDT) CPU, there's no practical reason to opt for a cooler with a massive three-fan radiator. For most mainstream platforms, something more modest will suffice.

Performance isn’t the only reason people look into buying a new cooling device for their PC. Quiet operation is often also a key consideration, especially if you’re building or upgrading a media PC for the living room or an office PC in an environment where fan noise would be disruptive. Plenty of enthusiasts and gamers prefer a quiet system.

The included coolers bundled these days with most AMD and Intel CPUs (Intel’s unlocked “K” SKUs notably don’t come with coolers) will generally do an adequate job, but Intel stock coolers, in particular, may not be as quiet as you’d like, even at stock CPU settings.

Here’s a quick comparison of some of the pros and cons of air and liquid cooling, to help narrow down your considerations. If you know what basic type of cooler you’re after, be sure to check out our picks for the best coolers of 2020. There you’ll find all of our favorite options for air and liquid cooling, based on years of testing hundreds of models.

Quick Shopping Tips

• Own a recent Ryzen CPU? You may not need to buy a cooler, even for overclocking. All Ryzen 300- and 2000-series processors and some older Ryzen models ship with coolers, and many of them can handle moderate overclocks. If you want the best CPU clock speed possible, you’ll still want to buy an aftermarket cooler, but for many Ryzen owners, that won’t be necessary.

• Check clearances before buying. Big air coolers and low-profile models can bump up against tall RAM and even VRM heat sinks sometimes. And tall coolers can butt up against your case door or window. Be sure to check the dimensions and advertised clearances of any cooler and your case before buying.

• More fans=better cooling, but more noise. The coolers that do the absolute best job of moving warm air away from your CPU and out of your case are also often the loudest. If fan noise is a problem for you, you’ll want a cooler that does a good job of balancing noise and cooling.

• Make sure you can turn off RGB. Many coolers these days include RGB fans and / or lighting. This can be a fun way to customize the look of your PC. But be sure there’s a way, either via a built-in controller or when plugging the cooler into a compatible RGB motherboard header, to turn the lights off without turning off the PC.

How much can you spend?

Budget is probably the first thing you should consider. In general, air coolers start out much cheaper than alternatives, at around $25 (£19) less than any AIO, and the most expensive air coolers (around $100 or £78) can still be cheaper than many comparable AIOs. In short, you’ll usually get more cooling performance per dollar with an air cooler.

AIO coolers start off a bit higher than air, around $60 (£45), and can run well over $150 (some models in the UK cost over £200) depending on the brand, size, and features. In general, the larger the radiator and more RGB LED fans and lights, the more it will cost. AIO coolers typically work well in RGB LED ecosystems, with their fans supporting not only their own brand’s ecosystem/software but compatible with software from board makers as well.

Finally, building a custom liquid loop will cost the most money by far. Between the radiator, pump, tubing, fittings, and the CPU block,  the total cost is going to be significantly higher than a closed-loop kit. What does this increased cost get you? Depending on the configuration, you can can get better performance, as well as the ability to customize the setup completely, with different coolant or tube colors, and the possibility of adding cooling to other components, like the graphics card, as well.

But custom water loops aren't for everyone, regardless of price. The chance of a leak in a custom system is a lot higher than in a closed system, especially if you don’t have experience building custom cooling loops. That said, when done right, the overall risk of a leak is low.

How do I know what will fit in my system?

Whether you’re opting for air, an AIO, or custom water loop, you need to make sure it's not too big. Factors here include the CPU socket as well as any potential chassis limitations for things like cooler height or radiator size. Most air coolers and closed-loop coolers offer a wide range of support for both AMD and Intel processors/sockets.

Typically, these devices include mounting hardware for several sockets, increasing compatibility across a wide range of sockets. We usually see the most popular models support Intel 1200, 115x, 2066, and 2011-v3 sockets. On the AMD side, support often includes AM2/AM2+, AM3, AM3+, and AM4.

The notably larger Threadripper processors have their own mounting and larger cold plate areas to better cool the acreage on the integrated heat spreader, so support for those is limited mostly to coolers designed for them, which often have the socket (TR4) name in the product. See, for example, the Noctua NH-U12S TR4-SP3.

On the case side, it’s important to look at specifications for what size heatsink or radiator is supported. Chassis manufacturers usually list the maximum cooler height allowed, and heatsink makers will always list the dimensions of their coolers. Another consideration with air coolers is the amount of clearance under the cooler for the RAM slots. If you plan to use DIMMs with tall heat spreaders on them, you must make sure that your cooler allows enough clearance above the motherboard for your memory.

Below is an example of how dimensions are often listed, from a Noctua cooler manual.

For liquid cooling, either AIO or a custom loop, the number and size of radiators your case will support is key for deciding how many radiators you can install and how big they can be. Case manufacturers also typically list the radiator mounting locations and sizes.

Be careful with top-mounted radiators, because the total height of the radiator and your chosen fans can interfere with the top of the motherboard and its 8-pin power connector. Even if you have enough room, you’ll probably need to make sure that power connector is plugged in before installing your radiator and fans.

What Type of CPU Cooler is best for me, air or water?

If price and ease of install are your primary concerns, an air cooler is likely your best choice. Cooler Master’s under-$40 Hyper 212 RGB offers better performance than stock cooling solutions without adding much to your build budget. For a bit more, one of the best air coolers on the market is the be quiet! Dark Rock 4 ($75).

However, if you want a quieter PC with lower CPU temperatures, a water-based cooler is probably for you. Just plan to spend more money. A high-end AIO with a 280mm or 360mm radiator (like the CoolerMaster MasterLiquid ML360R RGB) will outperform--albeit sometimes not by much--most air coolers on the market. But unless your case is quite large, a three-fan radiator may not fit in your PC anyway.

There are also expandable kits available on the market like the Swiftech Drive x3 AIO ($165) which lose the CLC (closed loop cooler) nomenclature, allowing you to expand the cooling loop to other components, much like a custom loop than a sealed kit.

If you're paying mid-range prices (less than $125) and don't plan to set any records, both aftermarket air coolers and mid-range AIOs are plenty capable of keeping most processors within safe temperature ranges, including when overclocking. Key differences mostly come down to aesthetics and pricing. Products like the Corsair H100i Pro ($115) fall into this mid-range category, as does the Cooler Master MasterAir MA410M ($63) on the air-cooled side.

Whatever cooler you're considering, check the TDP rating. In a lot of cases, air and AIO cooler specifications will also list the TDP rating (how much heat the cooler can dissipate), which is a good way to determine the capacity of the chosen unit. If the TDP of your processor is higher than what your cooler lists, chances are your CPU will throttle or your fan will run loud all the time (or both). But if the cooler is rated higher than the TDP of your CPU, temperatures should be lower and so should noise.

Bottom Line

Whether you're looking to overclock your PC to its highest potential or just prevent throttling at stock speeds, you need to pay close attention to your CPU cooler. If you don't have huge ambitions and you're using a Ryzen chip, you may be able to save money by sticking with the stock cooler that came in your box. But otherwise, you should make sure you check the space and TDP requirements before choosing the right solution for your system.

Finding Discounts on CPU Coolers

Whether you're shopping for one of the products that made our best CPU coolers list or one that didn't, you may find some savings by checking out our list of Newegg promo codes, Best Buy promo codes or Corsair coupon codes.