Noctua NH-D15


This cooler doesn’t care what processor you are pairing with it because its cooling performance is excellent enough and you can nearly overclock any CPU with it. When it comes to air coolers, no other competitor is offering the same value and performance we are getting with NH-D15.

When it comes to its performance, you will notice that it’s giving the same thermals which users are getting from 280mm AIOs but for a low price. High performance of an air cooler means the bulkier size, and it comes with two heatsinks which makes it too large. There are two fans from which one is on the front and second is sandwich between the heatsinks. This combination makes excellent airflow between the heatsink fans and makes it cool down.

There are six heatsink pipes connecting both of the heatsinks and the CPU block and dissipates much heat while the 120mm fans blow heat on tower heatsinks and allow great OC power. The bulkier design of this cooler asks you to get at least a mid-tower case and an ATX motherboard so that you can easily install it.

One thing that confuses many users about this cooler is the RAM clearance because of its size. You can’t install this cooler on ITX motherboards while ATX and m-ATX motherboards support it but don’t get some tall memory sticks. When it comes to casings, you can nearly fit this cooler in any casing available in the market but make sure you are not going with ITX casings.

The installation of this cooler is not easy at all, and I would recommend you remove the motherboard first and install the cooler. If you’ve never installed an air cooler before you may face some problems while installing it, check out its manual guide.

Apart from installing another major downside of this cooler, the price is too high, but it justifies its price for the performance. Of course, it’s way cheaper than AIOs but offering the same performance while looking at the competitors that are slightly cheaper than it but cuts of some performance.

Zalman CNPS20X


There are a couple of things that we were missing in the Noctua NH-D15, like the aesthetics, and the major downside of that cooler was the too high price. Though there, we’ve got a cheaper option of that cooler that you might also like to get, and it offers more than NH-D15 except for the performance. There are RGB fans on this cooler, and it comes in a completely black color body, which looks compelling in color coordinate builds and gives excellent aesthetics. Like the aforementioned cooler, this one also has two heatsinks connected and the CPU block with six heatsink pipes.

The two fans of this cooler produce significant RGB effects, but sadly, they go a bit loudly when the CPU runs high on loads. Though your casing is well closed, this might not affect you because that noise is not too much. This cooler’s bulkier size allows maximum heat dissipation and gives decent cooling performance when you are overclocking some high-end processor.

Most of us can easily install the cooler, while few non-techy guys may find it hard to install because of the large size. I would recommend you properly check out this cooler’s manual before putting your hands to install it. The memory clearance of this cooler is adequate, and you are not going to face any issue unless you are using some tall memory sticks which can block the cooler. The cooler’s biggest downside reported by the users is cleaning it as its size is slightly larger than others, so it’s hard to clean the cooler. Overall, it’s one of the best options you can consider for your build regarding this cooler’s performance.

Be Quiet! Dark Rock Pro 4

MODEL Dark Rock Pro 4

Next on the list is another excellent alternative of NH-D15 but as the name suggest this cooler is one of the quietest one and with it, you are not going to listen to any fan noise. Lowering this cooler’s noise doesn’t mean that you have to compromise on the performance because it’s comparable to most premium coolers while it comes slightly lower than them.

If you are looking for an absolute silent cooler, this one is made for you, and I’m sure that it will never disappoint you in terms of performance or noise level. There are two fans on this cooler, which runs at 1500 RPM and has two heatsinks connected with seven heatsink pipes. This cooler’s size is slightly larger than standard coolers, and you may face some problems while installing or removing it and need to be careful about that. One thing that impressed me about this cooler is the aesthetics as it doesn’t have RGB lights, but the black colored body of it picks colors to form RGB lights installed in the casing and makes it compelling in RGB builds. This cooler’s weight is more than a kilogram, which can cause problems while installing the processor, and I would recommend you remove your motherboard from the casing during the installation.

The impressive design and low noise make this cooler one of the appealing choices for users who are tired of listening to fans' loud noise from their computers. Be Quiet played well in the game and made this cooler comparable with some of the premium air coolers in the market, and I would say it’s one of the best coolers for i9 9900k.

Deep Cool Assassin III

MODEL Assassin III

Those users who don’t like the color scheme of Noctua NH-D15 or are willing to get something different can try the Deep Cool Assassin III, as this cooler is an excellent alternative. This cooler’s performance is not equalled t that cooler nor better than that; instead, it is somewhere close to it, and we can compare both of them for the same price. D15 has a significant advantage because the noise level as that cooler runs at absolutely zero noise while this one has little noise problem when running high on loads.

Like all the coolers mentioned above, this one has the same installation problem. It is tremendous in size and has dual heatsinks, making the installation process difficult, especially for non-techy users. I like the most about this cooler because its performance is similar to a 289mm AIO, while it’s a lot cheaper than that, which allows the same overclocking support for flagship processors. Overclocking i9 9900K to 5K is quite tricky with this cooler, and you need to go with some better options. Still, under 5GHz can be achieved easily, and you will enjoy your processor’s performance in games and applications.

Aesthetically this cooler is pretty straightforward, and you are not going to see compelling components or RGB lights on it; instead, there are simple black colored fans and a silver heatsink. The two heatsink pipes are connected through heatsink pipes and connect the CPU block with them, which dissipates much heat. Overall for performance, it’s a great choice that you can consider for your gaming build.

Thermalright Le Grand Macho RT

MODEL Le Grand Macho RT

The aforementioned coolers are slightly expensive for a mid-range build, so I’ve researched a bit more and got the cheapest option that you can also pair up with the i9 9900K without compromising on the overclocking. Le Grand Macho RT from Thermalright is one of the cheapest coolers for high-end processors and offers excellent performance and noise dumping. This cooler has a large heatsink and a single non-RGB fan that comes pre-installed on it.

This cooler’s heatsink is connected with the CPU block with seven heatsink pipes, which also helps take away heat from the lower section to the upper one. Then a 140mm fan blows air on the heatsink vents to make it cool down, and this makes an excellent and efficient cooling process that allows you to overclock your processor. The compatibility of this cooler is excellent enough. You can put it on any Intel or AMD socket, but the installation is a bit challenging because of its bulkier size. When it comes to RAM clearance, you will not face any problem unless you do not use tall memory sticks, but the expansion slot clearance could be much better. There are several variants of this cooler, as you can get it with fans or without fans or get two pre-installed fans with it, so it’s good that you can get it according to the budget and needs.

The downside of this cooler is that the expansion slot clearance is not as good as it needs to be because of the large-sized heatsink, and while installing or removing it can damage the graphics card; it’s good to remove the GPU first before removing it. Also, the manufacturers are giving only 1-year of warranty while we’ve seen other manufacturers giving up to 10-years of warranty.

Corsair iCUE H100i


When you are considering an AIO, most users look for two things: the premium performance and the other is the aesthetics. Corsair gives both of them at the same place with their iCUE H100i, where you are likely to see the decent performance while overclocking high-end processors and RGB lights make this cooler pleasing in builds. The fans' noise is not compromised because this cooler is one of the most silent working on among the competitors. Comparing it with other alternatives in the market, you may feel a slight performance difference, but it leads the game to the noise level of fans.

With all these great features, this cooler’s price is slightly higher than the competitors, at least the MSRP, but you can get it for cheap at some deal if looking for a silent AIO. Also, this cooler’s overclocking performance for i9 9900K makes its price understandable and makes it a worthwhile deal for this build. There is iCUE software that comes bundled with this cooler, and it helps you produce different RGB effects from the RGB lights on it and change the thermal performance of this cooler according to how much you are willing to overclock your processor. We’ve tested some temperature tests in this cooler, and they might probably help you while deciding the cooler. The boost clock of i9 9900K can be easily achieved with this AIO, and you are not going to listen to fan noise even at that frequency.

This cooler’s price might be slightly higher than others, but with all of these features, it’s understandable, and it will be a worthwhile deal for i9 9900K. The iCUE software allows you to manage the cooler lights and thermal controls, and you don’t need to go with some third party software for it. When i9 9900K is overclocked to 5 GHz, this cooler’s temperature goes to 82 degrees Celsius, while at full loads and stock clocks, it doesn’t go over 74 Celsius. The idle temperature of this cooler is 38, which is pretty impressive for a flagship processor. This cooler’s major downside is the extreme price, while a few users feel it awkward to see small screws securing the fans at the radiator.

Corsair Hydro H150i Pro RGB

MODEL Hydro H150i Pro RGB

The aforementioned cooler was not that good in terms of performance. Still, if you are looking for something similar to the better performance, we’ve got another consideration for you from the same manufacturer. There is Hydro H150i Pro RGB from Corsair that’s the same as this cooler mentioned above in term of aesthetics and noise level but offers better performance than that, which gives it an advantage for the same price, and you can consider it if looking for more thermal performance to overclocking your i9 9900K at some great extent.

This cooler comes with two RGB fans, which produces excellent effects while spinning, and you can customize the RGB lights to make them match the impact of other RGB lights on the build. The CPU block of this cooler also comes with RGB lights, and the build quality of it is impressive, which most of us expect from Corsair as it’s a well-reputed brand. The most exciting this about this cooler is it comes in three different variants, which vary the radiator size, and you can select the one that fits best under your budget and your needs. The fans of this cooler run at the max speed of 1600 RPM but still don’t make any noise, and we need this speed usually when the CPU is overclocked or running at full load. If you are looking for a budget cooler, it’s not for you because of its high price. Long story short, it’s a great cooler that you can consider for your gaming build that allows you to do some serious overclocking with your processor.