Overclocking an i7-6800K pushes a 140W six-core X99 chip well beyond its rated power, and finding a strong cooler that still supports LGA 2011-3 is the hard part. This guide to the best CPU coolers for i7 6800K overclocking compares six high-headroom options, mostly AIOs plus two dual towers, that list X99 support.
Quick verdict
For an overclocked i7-6800K, the ARCTIC Liquid Freezer II 280 A-RGB is the strongest pick we could verify with X99 support: a 280mm AIO whose Amazon spec lists LGA 2011-3 and 2066. If you want 360mm of radiator for less money, the be quiet! Pure Loop 2 FX 360 lists 2011-3 square ILM. The Phantom Spirit 120 EVO is the air alternative.
| Cooler | Type | Radiator or height | X99 listed | Best for | Amazon US, Nov 2026 |
|---|---|---|---|---|---|
| ARCTIC Liquid Freezer II 280 A-RGB | 280mm AIO | 280mm radiator | 2011(-3), 2066 in spec field | Best overall for overclocking | about $100 |
| be quiet! Pure Loop 2 FX 360 | 360mm AIO | 360mm radiator | 2011(-3) square ILM | Most radiator per dollar | about $70 |
| Cooler Master MasterLiquid ML240L RGB V2 | 240mm AIO | 277 x 119.6 x 27.2mm | 2011-v3, 2066 | Proven 240mm AIO | about $90 |
| Thermalright FW 240 SE ARGB Black | 240mm AIO with LCD | about 277mm long | 2011, 2066 | Budget AIO with screen | about $59 |
| Thermalright Phantom Spirit 120 EVO | Dual-tower air | 157mm | 2011 in title | Overclocking on air | about $47 |
| Thermalright Peerless Assassin 120 Black | Dual-tower air | Not separately verified | 2011, 2066 in title | Budget black air | about $39 |
How we selected overclocking coolers for the i7-6800K
Intel lists the i7-6800K with six cores and 12 threads, 3.4GHz base and 3.6GHz turbo, Turbo Boost Max 3.0 up to 3.8GHz, a 140W TDP and a 67.2 Tcase, on the FCLGA2011 socket used by X99, launched in the second quarter of 2016 without a cooler in the box. Raising the multiplier and voltage lifts power well above 140W.
So we prioritized radiator area and dual-tower capacity, and every pick had to list LGA 2011, 2011-3 or 2066 on its maker page, Amazon listing or spec table. Few current coolers still do. This is a research roundup from spec pages and Amazon US data gathered in November 2026; we did not run overclocks or measure temperatures, so results will depend on your chip.
Our companion i7-6800K guide covers quiet stock operation with large air coolers. This one targets overclockers, so it leans on AIOs. Because X99 support is rare, a few picks also appear in our i7-5820K guide, which covers a closely related six-core Haswell-E chip on the same platform.
Best CPU coolers for i7 6800K overclocking, reviewed
Each review covers which overclocking setup the cooler suits, its verified specs, the Amazon rating snapshot and its weaknesses. Ratings and prices are November 2026 snapshots and will change. Where X99 support appears only in a listing’s spec field or title, we flag it so you can check the box contents before installing.
ARCTIC Liquid Freezer II 280 A-RGB
The Liquid Freezer II 280 A-RGB is our top overclocking pick. Its Amazon listing gives fan speeds of 200 to 1900 RPM, a PWM-controlled pump, 24 digital A-RGB LEDs and fan cables routed inside the hose sleeve, and its compatibility field lists Intel 1150, 1151, 1155, 1156, 1200, 1700, 2011(-3) and 2066 plus AM4 and AM5.
A 280mm radiator with two 140mm-class fans gives more surface area than a 240mm unit, which matters for an overclocked six-core. It is an older generation than ARCTIC’s current Liquid Freezer III, which we excluded because its listed Intel support stops at LGA 1700 and 1851 without separate kits that do not mention X99.
It was rated 4.4 out of 5 from about 750 Amazon ratings and listed around $100 on Amazon US as of November 2026. Check that your case has a 280mm mount, since many X99-era cases support only 240mm or 360mm.
- Pro: X99 and X299 sockets listed in the spec field
- Pro: integrated cable routing keeps the build tidy
- Con: older generation; we found no ARCTIC page for current availability
- Con: needs a 280mm radiator mount
Buy it if your case has a 280mm mount and you want the most capable verified X99 AIO here. Skip it if your case only takes 240mm.
be quiet! Pure Loop 2 FX 360
The Pure Loop 2 FX 360 offers the most radiator for the money. Its Amazon listing lists Intel 1700, 1200, 2066, 1150, 1151, 1155 and 2011(-3) Square ILM plus AM5 and AM4, three Light Wings 120mm PWM high-speed fans, a doubly decoupled PWM pump and an ARGB-PWM hub for up to six devices.
Three fans on a 360mm radiator spread an overclocked 6800K’s heat widely, which lets them run slower than a 240mm unit at the same load. A published review of the Pure Loop 2 line describes a refill port on the radiator. The Amazon spec table lists a one-year warranty, which we could not confirm with be quiet!.
It was rated 4.6 out of 5 from about 590 Amazon ratings and listed around $70 on Amazon US as of November 2026. A 360mm mount is the main requirement.
- Pro: explicit LGA 2011(-3) square ILM support
- Pro: 360mm radiator for about $70
- Con: needs a 360mm mount
- Con: warranty term unclear
Buy it if your case takes a 360mm radiator. Skip it if it does not.
Cooler Master MasterLiquid ML240L RGB V2
The ML240L RGB V2 is the safe 240mm choice. Its Amazon listing gives a 277 x 119.6 x 27.2mm radiator, a third-generation dual-chamber pump and two SickleFlow 120mm RGB PWM fans, with Intel LGA 2066, 2011-v3, 2011, 1366, 1200 and 115x plus AMD AM4 listed. LGA 1700 needs a separate kit.
A 240mm radiator is smaller than the two picks above, so it suits a moderate overclock rather than the most aggressive one. Its strength is a very large review base and explicit 2011-v3 hardware support.
It was rated 4.6 out of 5 from about 9,600 Amazon ratings and listed around $90 on Amazon US as of November 2026, by far the most reviewed cooler here. A 240mm mount fits most cases.
- Pro: explicit LGA 2011-v3 support and huge review base
- Pro: 240mm fits most X99-era cases
- Con: less radiator area for heavy overclocks
- Con: priced close to the larger Freezer II 280
Buy it if your case only takes 240mm and you want a well-proven AIO. Skip it if you can fit a 280mm or 360mm radiator.
Thermalright FW 240 SE ARGB Black
The FW 240 SE ARGB Black is the budget AIO with a display. Its Amazon listing describes a 320 x 240 IPS LCD that attaches magnetically and can show custom images, and lists AMD AM4 and AM5 plus Intel LGA 1150, 1151, 1155, 1156, 1200, 2011, 2066, 1700 and 1851, with mounting hardware for each.
The listing’s title mentions 360mm, but its 10.91-inch length matches a 240mm radiator, so treat it as a 240mm unit. Fan and pump specs are not clearly stated in the data we checked, which is the main reason it ranks below the ML240L RGB V2.
It was rated 4.4 out of 5 from about 165 Amazon ratings and listed around $59 on Amazon US as of November 2026. The small review base and unclear specs make this a pick for builders who want the screen.
- Pro: LCD display and X99 support at a low price
- Pro: lists LGA 2011 and 2066 hardware
- Con: confusing title and unverified fan and pump specs
- Con: small review base
Buy it if you want a screen on a budget X99 AIO. Skip it if you want fully documented specs.
Thermalright Phantom Spirit 120 EVO
The Phantom Spirit 120 EVO is the air option for overclockers. Its Amazon listing gives 125 x 135 x 157mm, seven 6mm heat pipes and two TL-K12 fans up to 2150 RPM, 69 CFM and 27 dB, and its title lists Intel 1700, 1150, 1151, 1200, 2011 and 1851 plus AM4 and AM5.
Seven heat pipes and fast fans give real headroom for an overclocked six-core without a pump. The listing says LGA 2011 rather than 2011-3, so confirm the X99 studs are in the box before removing your current cooler.
It was rated 4.8 out of 5 from about 520 Amazon ratings and listed around $47 on Amazon US as of November 2026, the highest rating here. At full speed its fans will be loud, which is the trade for headroom.
- Pro: seven heat pipes and 2150 RPM fans
- Pro: no pump to fail
- Con: listing names 2011, not 2011-3
- Con: loud at full fan speed
Buy it if you prefer air for overclocking. Skip it if your case allows under 160mm.
Thermalright Peerless Assassin 120 Black
The PA120 Black is the budget air choice for a moderate overclock in a black build. Its Amazon title lists Intel LGA 1700, 115X, 1851, 1200, 2066 and 2011 plus AM4 and AM5, six heat pipes and a TL-C12B PWM fan. We found no separate maker page for this variant, so height and fan count are unverified.
It has one fewer heat pipe and slower fans than the Phantom Spirit 120 EVO, so it suits a moderate overclock better than a maximum one. If you want documented specs, the standard Peerless Assassin 120, whose maker page lists LGA 2011-3, is the alternative.
It was rated 4.8 out of 5 from about 290 Amazon ratings and listed around $39 on Amazon US as of November 2026.
- Pro: all-black look with X99 listed
- Pro: strong rating at a low price
- Con: specs not confirmed by a maker page
- Con: less headroom than the EVO
Buy it if you want a black dual tower for a mild overclock. Skip it if you need documented height.
Buying guide for overclocking an i7-6800K
Overclocking on X99 adds heat at the CPU and at the board’s VRMs, so cooler choice, case layout and fan control all matter. These checks cover radiator size, X99 mounting, VRM airflow and fan setup, the areas that decide how far a 6800K overclock can go before temperatures stop you.
Radiator size and headroom
For an overclocked 140W six-core, more radiator area generally means lower fan speeds at the same load. A 360mm unit like the Pure Loop 2 FX 360 or a 280mm unit like the Liquid Freezer II gives more margin than a 240mm AIO, and the extra fan area also helps keep noise down during long stress tests or renders.
Match the radiator to your case first. Check both the mount and the fan thickness, and leave room for tubing to reach the socket without straining the fittings.
Confirm X99 mounting hardware
X99 uses LGA 2011-3 with a square ILM, and most current coolers no longer include hardware for it. Each pick here lists LGA 2011, 2011-3 or 2066 somewhere, but several do so only in the listing title or spec field rather than on a maker page, which leaves room for a missing bracket in the box.
Before removing your old cooler, confirm the box contains the X99 studs or bracket. Noctua’s spec tables, for example, show Square ILM support only with a separate kit for some models, and other brands may differ.
VRM airflow with AIOs
With an AIO, the fan that a tower cooler would point across the socket area is gone, so the board’s VRM heatsinks may get less airflow during an overclock, when they work hardest. A front intake plus a rear or top exhaust, with the radiator fans set as exhaust, helps keep fresh air moving past the socket.
The Liquid Freezer II 280 A-RGB listing does not mention a VRM fan, so plan case airflow around the socket area accordingly.
Fan and pump control
Connect the pump to a header running at a fixed or high speed if the manual says so, and put the radiator fans on a PWM curve tied to CPU temperature. That keeps the pump steady and the fans quiet until a sustained overclocked load pushes temperatures up.
The Pure Loop 2 FX 360’s hub and the Freezer II’s single-cable design simplify wiring on boards with limited headers.
FAQ
These answers cover the overclocking questions i7-6800K owners raise most, including AIO versus air, radiator size and why many popular coolers do not fit. They rely on Intel’s spec page and the listings above, without our own overclock results or temperature claims.
Which of the best CPU coolers for i7 6800K overclocking fits most cases?
The Cooler Master MasterLiquid ML240L RGB V2. Its 240mm radiator fits more X99-era cases than 280mm or 360mm units, and its listing names LGA 2011-v3 directly. It has less headroom than the Liquid Freezer II 280 A-RGB or Pure Loop 2 FX 360, but it is the easiest fit.
Is air cooling enough to overclock an i7-6800K?
For a moderate overclock, a strong dual tower like the Phantom Spirit 120 EVO can work, and it has no pump to fail. For a heavier overclock with higher voltage, a 280mm or 360mm AIO gives more margin. Your chip’s own limits and your case airflow matter as much as the cooler choice.
Why can’t I use an ARCTIC Liquid Freezer III on X99?
ARCTIC’s current Liquid Freezer III pages list Intel LGA 1700 and 1851 with a contact frame, and the separate LGA 1200/115X kit adds older mainstream sockets but not LGA 2011-3. That is why the older Liquid Freezer II 280 A-RGB, whose listing includes 2011(-3), is the ARCTIC pick here.
Conclusion
Buy the ARCTIC Liquid Freezer II 280 A-RGB to overclock an i7-6800K if your case has a 280mm mount; its listing names LGA 2011(-3) and its larger radiator gives the most verified headroom here. If your case takes 360mm, the Pure Loop 2 FX 360 is the cheaper alternative, and the ML240L RGB V2 fits most other cases.
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