Choose the AIO radiator size that your case supports at the mounting position you plan to use, then compare the exact cooler dimensions and clearances. A 360mm radiator gives you more surface area to work with, but its size alone does not guarantee a specific temperature, noise, or value advantage over a 240mm model. If your case only supports 240mm at the top, for example, a 360mm cooler may fit at the front but not where you want it.
What changes between a 240mm and 360mm AIO?
The number describes the radiator format, not its full length or the space the installation needs. As an example, Lian Li lists its GALAHAD AIO 240 radiator at 273 × 123.5 × 27mm and the 360 version at 397.5 × 123.5 × 27mm (Lian Li product page). Fans add to the total thickness, and the case must also have enough room for the radiator’s length and width.
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In general, a 360mm radiator offers more surface area than a 240mm one. Corsair advises using as much radiator surface area as the case can accommodate, and suggests a thicker 240mm radiator as one possible alternative when a 360mm radiator will not fit (Corsair radiator guidance). That is a general design consideration, not proof that one particular 360mm AIO will outperform every 240mm model. The sources cited here do not provide a controlled, like-for-like temperature or noise comparison for specific coolers.
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Check the case manual or official compatibility chart for the exact mounting position: front, top, or another location. Support can differ by position. MSI’s cooler-buying guidance emphasizes that the radiator, rather than the CPU socket, is often the installation challenge; it recommends checking the chassis support and the combined radiator-and-fan thickness against nearby VRMs, EPS cables, and memory (MSI cooler guidance).
#1 Best Overall
- CONTACT FRAME FOR INTEL LGA1851 | LGA1700: Optimized contact pressure distribution for longer CPU life and better heat dissipation
- ARCTIC's P12 PRO FAN: More power at any speed - more powerful and quieter than the P12, especially at low speeds. Higher maximum speed for optimal cooling performance under high load
- NATIVE OFFSET MOUNTING FOR INTEL AND AMD: Shifting the cold plate center towards the CPU hotspot ensures more efficient heat transfer
- INTEGRATED VRM FAN: PWM-controlled fan that lowers the temperature of the voltage converters and thus ensures reliable performance
- INTEGRATED CABLE MANAGEMENT: The PWM cables of the radiator fans are integrated in the sheathing of the hoses so that only a single visible cable is connected to the motherboard
Case charts can allow different sizes in different positions
DeepCool lists the CC360 WH ARGB as supporting a 360mm radiator at the front but only a 240mm radiator at the top (DeepCool CC360 WH ARGB specifications). A 360mm cooler is therefore not automatically an option for every mount in a case that supports one somewhere.
Clearance may depend on other installed parts
Some compatibility charts include conditions beyond radiator size. Fractal Design’s Define R5 chart lists front 240mm and 360mm support, but a 360mm front radiator requires removing the ODD and HDD cages. The chart also restricts combining that installation with a 360mm or 420mm top radiator, and defines total thickness as radiator plus fans (Fractal Design Define R5 compatibility chart).
Rank #2
- Simple, High-Performance All-in-One CPU Cooling: Renowned CORSAIR engineering delivers strong, low-noise cooling that helps your CPU reach its full potential
- Efficient, Low-Noise Pump: Keeps your coolant circulating at a high flow rate while generating a whisper-quiet 20 dBA
- Convex Cold Plate with Pre-Applied Thermal Paste: The slightly convex shape ensures maximum contact with your CPU’s integrated heat spreader, with thermal paste applied in an optimised pattern to speed up installation
- RS120 ARGB Fans: RS ARGB fans create strong airflow and high static pressure, with easy ARGB control via a compatible motherboard. CORSAIR AirGuide technology and Magnetic Dome bearings ensure great cooling performance and low noise
- Easy Daisy-Chained Connections: Reduce the wiring in your system by daisy-chaining your RS ARGB fans and connecting them to just one 4-pin PWM fan header and one +5V ARGB header
For the AIR 5400 specifically, Corsair lists a maximum combined radiator-and-fan thickness of 70mm and calls for at least 380mm of tube length, with 400mm or more preferred. Those are AIR 5400 requirements, not universal AIO standards (Corsair AIR 5400 compatibility guidance).
How to compare two actual coolers
- Choose a mounting position. Confirm that your case officially supports the radiator size at the front, top, or other location you intend to use.
- Compare full dimensions. Use the cooler’s actual radiator length, width, and thickness, then add fan thickness. Check nearby motherboard components, memory, power cables, graphics card, and other installed hardware.
- Check installation constraints. Look for tube-length requirements, drive-cage removal, limits on combining radiators, and any other conditions in the case chart.
- Verify CPU compatibility and mounting hardware. Use the current product page and manual for the exact AIO model and your CPU socket. For example, Corsair lists the H100 RGB as a 240mm AIO and the H150 RGB as a 360mm option, with socket support including Intel LGA 1700/1851 and AMD AM4/AM5 (Corsair H100 RGB product page). Confirm the support and hardware for the particular model you are considering.
- Compare measured performance, noise, and price for the models themselves. To judge cooling or noise, look for testing that identifies the exact coolers, CPU, workload, ambient conditions, and fan settings. Radiator size labels alone do not establish a temperature difference, noise ranking, or price-per-performance winner.
Which size should you choose?
Choose a 360mm AIO when
- Your case supports a 360mm radiator at your preferred mounting location, with enough room for the complete radiator-and-fan assembly.
- The installation does not conflict with other hardware or require trade-offs you are unwilling to make, such as removing a drive cage.
- You want the additional radiator surface area and have verified the exact cooler’s fit, socket support, and mounting hardware.
Choose a 240mm AIO when
- Your preferred case position supports 240mm but not 360mm, or the larger assembly conflicts with other components.
- You have checked the specific 240mm cooler’s dimensions and installation requirements rather than assuming that every model will fit.
- A 240mm model better suits your installation constraints. A thicker radiator may be an option in some builds, but radiator and fan thickness still need to fit the case.
In short, do not buy by the “240mm” or “360mm” label alone. Check your case’s position-specific compatibility chart and compare the exact AIO and case dimensions. Consider cooling performance, noise, and value only through evidence for the specific models you are comparing.
Quick Recap
Rank #4
- Simple, High-Performance All-in-One CPU Cooling: Renowned CORSAIR engineering delivers strong, low-noise cooling that helps your CPU reach its full potential
- Efficient, Low-Noise Pump: Keeps your coolant circulating at a high flow rate while generating a whisper-quiet 20 dBA
- Convex Cold Plate with Pre-Applied Thermal Paste: The slightly convex shape ensures maximum contact with your CPU’s integrated heat spreader, with thermal paste applied in an optimised pattern to speed up installation
- RS120 ARGB Fans: RS ARGB fans create strong airflow and high static pressure, with easy ARGB control via a compatible motherboard. CORSAIR AirGuide technology and Magnetic Dome bearings ensure great cooling performance and low noise
- Easy Daisy-Chained Connections: Reduce the wiring in your system by daisy-chaining your RS ARGB fans and connecting them to just one 4-pin PWM fan header and one +5V ARGB header
Rank #3
- CONTACT FRAME FOR INTEL LGA1851 | LGA1700: Optimized contact pressure distribution for longer CPU life and better heat dissipation
- ARCTIC's P12 PRO FAN: More power at any speed - more powerful and quieter than the P12, especially at low speeds. Higher maximum speed for optimal cooling performance under high load
- NATIVE OFFSET MOUNTING FOR INTEL AND AMD: Shifting the cold plate center towards the CPU hotspot ensures more efficient heat transfer
- INTEGRATED VRM FAN: PWM-controlled fan that lowers the temperature of the voltage converters and thus ensures reliable performance
- INTEGRATED CABLE MANAGEMENT: The PWM cables of the radiator fans are integrated in the sheathing of the hoses so that only a single visible cable is connected to the motherboard
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
