The i9 9900k CPU may have been superseded by Intel’s batch of 10th-gen i9 processors released midway through 2020, but it still holds a worthy spot in a decked PC build. If you’ve got hands on one, or plan to take the plunge, and are on the hunt for some advice on a cooler with the chops to handle the processor, then you’ve come to the right place.
Buying the right CPU cooler is arguably one of the most crucial decisions you’ll make when piecing together a new build, notably if you have an eye on pushing the i9 9900k with some overclocking. A bad cooler can limit the CPU from reaching its full potential, produce unwanted noise levels, and even cause throttling in some instances. As such, choosing a cooler capable of dissipating the heat produced by i9 9900k under any load is of utmost importance.
A saturated market means an impressive, if a little disheartening, spread of CPU coolers available. Wading through them to settle on a winner can test even the most patient among us. We aim to take the hard work out of the equation and get you up and running with a cooler you won’t regret spending your hard-earned cash on. Without any further ado, let’s dive in.
Our selection process centered on assessing everything the market has to offer – the good, the bad, and the ugly – to find the very best i9 9900k cooler that money can buy. How did we go about choosing among a sea of options?
As we’re honing in on a product whose sole purpose is to ensure the i9 9900k runs at reasonable temperatures, whatever you throw at it, our trawl through the cooler options was guided by a focus on a few core criteria. Namely, price, cooling performance, build quality, potential installation hiccups, and noise levels. Of course, added non-essential extras, such as RGB lighting and ease of installation, factored to some extent into our selection.
From there, we narrowed down our choice to five models that, in our estimation, beat out the rest to offer i9 9900k owners a reliable CPU cooler.
Best CPU Cooler For i9 9900k in 2021
Excellent build quality.
First up, we have our top recommended CPU cooler for the i9 9900k. Masterminded by the engineering wizards over at Austrian manufacturer Noctua, this is one mighty air cooler, not just in stature, but in its ability to keep the heat produced by the i9 9900k in check.
While the beige and maroon color scheme won’t be to everyone’s liking (there’s a black model available), the Noctua NH-D15 features dual 140 mm fans sided by a duo of heatsinks boasting heat dissipation on par with many AIO liquid cooling solutions. Widely regarded as the best air cooler on the market, the Noctua NH-D15 is also incredibly quiet, capping out at 25 dB under the most demanding CPU loads.
The Noctua NH-D15 is relatively well priced given what it packs under the hood, although higher than more value options. Noctua also packs in a tube of its excellent NT-H1 thermal paste and a six-year warranty.
The only real downside is the size of the Noctua NH-D15, which towers at 165 mm. Consequently, it’s not suitable for small form factor builds and may dip into precious RAM heat spreader space, although Noctua has engineered it so that the front fan is removable to make space for RAM modules taller than 32 mm.
No nonsense AIO solution.
Size could be an issue for some builds.
If you’ve got your eye on a liquid-cooled setup, then look no further than the Corsair Hydro H150i Pro, which takes the crown as our top liquid CPU cooler.
As an All-in-One closed-loop CPU cooler, the Corsair Hydro H150i Pro channels the excellent cooling properties of water packaged in the company’s distinctive aesthetic, including an RGB low-noise pump, controlled by Corsair’s iCUE software. It’s a perfect option for those apprehensive about going the full custom loop but want a taste of liquid cooling in a manageable package.
Regarding the Corsair Hydro H150i Pro’s specifications, we are looking at a trio of PWN Magnetic Levitation 120 mm fans mounted on a chunky 360 mm radiator. Operational noise levels don’t go over 25 dB even under heavy loads, including modest overclocking, and CPU temperatures are kept well in check. This makes the Corsair Hydro H150i Pro one of the quietest liquid coolers out there.
One other excellent feature is the ease of installation thanks to Corsair’s modular, tool-free mounting bracket. However, the radiator’s size necessitates a large chassis and appropriate mounting real estate, so check dimensions before purchasing.
You’ll be paying more than an air cooler, but that comes with the territory, and the benefits of a closed-loop system are well worth the extra investment.
Ideal for overclocking.
Easy AIO installation.
High load noise levels higher than other options.
If you’re intent on pushing the overclocking capabilities of the i9 9900k, then a liquid cooler is the path to go down. More specifically, the NZXT Kraken X73 stands out as our top pick for overclocking.
We have another closed-loop All-in-One CPU cooler featuring three 120 mm fans with fluid dynamic bearings and a chamfered intake, a chunky 360 mm aluminum radiator, and tubes fitted with ultra-low evaporation rubber with braided nylon sleeves. NZXT has also thrown in easy installation and customizable RGB lighting effects on the pump.
The results are fan noise levels as low as 21 dB idle and under normal loads, and temperatures that far outclass most other air coolers, even when the CPU is overclocked. When pushed to dissipate rising heat levels, the fan churn can dart up to 36 dB, higher than other models in our guide but respectable.
Much like the Corsair Hydro H150i Pro, the NZXT Kraken X73 doesn’t come cheap, priced at nearly double the price of the more expensive traditional air cooler options out there. Similarly, NZXT Kraken X73 boasts a sizable footprint and consequently won’t suit all chassis sizes, so check dimensions beforehand.
As the name implies, the be quiet! Dark Rock 4 takes the trophy for the quietest CPU cooler for the i9 9900k. We are talking about a noise level peak of 21 dB, even under full load, which equates to near silence, given that the noise will be imperceptible when mixed in with the ambient noise of most rooms.
In terms of build, the be quiet! Dark Rock 4 is distinct for its sleek, all-black brushed aluminum diamond-cut finish design. It features a Silent Wings 135mm PWM fan with six-pole motor and fluid dynamic bearings, and six 6mm copper heat pipes with airflow-optimized wave-contoured cooling fins. There’s also the option to add in an extra 120 mm fan if required.
With such a focus on keeping noise levels to a minimum, the be quiet! Dark Rock 4 does take a hit when it comes to temperatures when compared to the Noctua NH-D15, but it falls within respectable limits nevertheless. Installation can be cumbersome, but nothing that is insurmountable.
In terms of performance-to-noise ratio, the be quiet! Dark Rock 4 is easily the most attractive air cooler option out there.
Price to performance ratio.
Chunky size and weight.
Our final pick is the Thermalright Le Grand Macho RT. This sprightly air cooler makes the mark as our top value CPU cooler for the i9 9900k. Its main attraction is the low price relative to the others on our list, but there’s the performance to match with one of the best price-to-performance ratios out there.
The Thermalright Le Grand Macho RT combines an ultra-low noise 150 mm PWN fan armed with fluid dynamic bearings and affixed to a 159 mm heat sink stacked with 35 proprietary holed fins for upped ventilation efficiency alongside nickel-plated heat pipes. Noise levels peak at around 30 dB for the most demanding loads, while temperatures never soar past 70 centigrade even when pushing the i9 9900k. We see here performance that edges very close to that of our top pick, the Noctua NH-D15.
The Thermalright Le Grand Macho RT is a hefty piece of kit and weighs in at 1.06 kg, and this is the only issue we can find to fault what is otherwise an excellent cooler. In most cases, the weight won’t be an issue as Thermalright has engineered a secure mounting mechanism that’s easy to install, but if you’re partial to carting your PC around, then caution is advised.
Things To Consider
Finding The Right Fit
Regardless of what type of CPU cooler you settle on, ensure it fits in your build. Our focus on i9 9900k suitability means all the options above are compatible with the LGA 1151 socket. We’re talking instead about considerations such as the height of the cooler or, in the case of AIO options, the size of the mounted radiator, RAM clearance, and, for small form factor builds, whether the CPU allows you to refit the panel at all.
Fortunately, case manufacturers list the upper limits for cooler size in official documentation widely available on their respective websites. A little research before laying down your cash should avoid any unwanted surprises when it finally comes to fitting a new CPU cooler.
Equally, cooler manufacturers often indicate the full dimensions of their products, and it’s worth checking they won’t gobble up valuable RAM real estate, especially if you’ve opted for memory with tall heat sinks. As for AIO options, check radiator mount positioning and dimensions on the documentation provided with your case.
Air or Water?
Are you torn between an air cooler and an All-in-One liquid cooler? Welcome to the club. Ultimately, the choice is subjective, and the right answer will vary greatly depending on who you’re asking.
The core point to remember is that liquid cooling generally curbs temperatures better than air variants and is often easier to mount, especially as the AIO offering from the likes of Corsair has matured in recent years. The temperature difference is more or less negligible unless you plan on venturing into serious overclocking territory.
The real differentiating factor is, however, affordability. Air coolers are broadly cheaper than liquid alternatives. With that comes less need for maintenance and the reassuring removal of the potential, however slim it might be, for component-damaging leaks. There’s also the space consideration: both air and liquid coolers need a place to call home, and not all builds have the requisite real estate, as we note in the section just above.
While price stands as the prime decider of what cooler you opt for, it’s worth considering your aims for your build. If you’re aiming to overclock your i9 9900k, then the demands placed on the cooler will be drastically different from those of low priced options. Grinding League of Legends daily or gunning for overclocking records place very different demands on your CPU. In other words, unless you plan on really pushing the chip, then there’s no sense in looking beyond a quality air cooler.
For those extreme overclockers out there, an AIO liquid cooler is by far the best option, and you may even want to explore open-loop or custom liquid cooling setups. They come with the price tag to match and their fair share of tinkering, but the heat dissipation is unparalleled.
You can’t go wrong with Noctua NH-D15. Mighty, reliable, and with an unmatched reputation, it should cater to nearly anything you can throw at the i9 9900k unless you plan on vying for the very best overclocks possible.
For those intent on going down the liquid cooler path, then the Corsair Hydro H150i Pro and the NZXT Kraken X73 are both excellent choices. As for the noise conscious out there, you really can’t falter when it comes to the be quiet! Dark Rock 4. Finally, the Thermalright Le Grand Macho RT air cooler falls on the lower on the price scale but offers an enviable price-to-performance ratio that should suit the i9 9900k’s stock speeds with some room to spare.
Our guide on the best cooler for Intel’s i9 9900k CPU now comes to a close. We hope our round-up of the best of what’s out there will ease the decision-making process and that you’ll settle on a product that suits your needs and stands the test of time. It’s worth reiterating that appropriate cooling is an essential consideration in any serious build and one that produces dividends for years to come if approached with the requisite dedication and research.
If you have any pressing questions or concerns, don’t hesitate to shoot us a message in the comment section below, and we’ll endeavor to answer back as quickly as possible.