When choosing an all-in-one (AIO) liquid cooler, the main decision is radiator size — 240mm, 280mm, or 360mm — and the assumption is "bigger is better." It's true that a larger radiator dissipates more heat, but the real-world gap between sizes depends entirely on how much heat your CPU produces. For a modest chip, a 360mm AIO is wasted money; for a hot, high-core CPU, it earns its place. This guide quantifies the difference and tells you when 240mm is plenty.
It builds on how to choose a CPU cooler and air vs liquid cooling in the Nigerian climate.
What Radiator Size Actually Changes
- More surface area = more cooling capacity: a 360mm radiator dissipates more heat than a 240mm, so it holds a hot CPU at lower temperatures, or runs quieter at the same temperature.
- The benefit scales with heat output: the gap between sizes is small under light load (the CPU isn't producing much heat) and grows under sustained heavy load.
- Diminishing returns: 280mm sits between 240 and 360; it often matches 360mm closely on capable units while fitting more cases.
Matching Size to Your CPU
- 240mm: plenty for most mid-range and even many high-end CPUs that aren't extreme heat producers. For a typical gaming CPU, a quality 240mm AIO (or a good air cooler) keeps temperatures comfortable.
- 280mm: a sweet spot — noticeably more capacity than 240mm, often near-360mm performance, if your case supports it.
- 360mm: for hot, high-core CPUs under sustained load (heavy rendering, a flagship chip), or when you want the lowest temperatures and quietest operation. See our flagship cooling guide.
The Honest Performance Gap
For a mid-range gaming CPU, the temperature difference between a 240mm and 360mm AIO is often modest — a handful of degrees — because the chip simply doesn't generate enough heat to stress either. The gap widens dramatically with a high-core CPU under heavy multi-threaded load, where the 360mm's extra capacity prevents throttling and keeps noise down. So the question isn't "which is best?" but "how much heat does my CPU make?" — buy the size that matches it, not the biggest you can fit.
The Nigeria Tax
Nigeria's warm ambient temperatures reduce every cooler's headroom, which nudges the decision slightly toward more capacity for hot CPUs — but it doesn't change the fundamentals: a 240mm is still plenty for a mid-range chip. Also weigh that a quality air cooler is more robust in dusty rooms and never leaks; for many builds it's the better choice than an AIO of any size. Match cooling to your CPU's heat and your environment, and don't overspend on radiator size you won't use.
Frequently Asked Questions
Is a 360mm AIO worth it over 240mm? Only for hot, high-core CPUs under sustained load, where the extra capacity prevents throttling and lowers noise. For a mid-range gaming CPU, the temperature gap is modest and a 240mm (or good air cooler) is plenty.
What size AIO do I need? Match it to your CPU's heat: 240mm for most mid-range and many high-end chips, 280mm as a sweet spot, 360mm for hot high-core CPUs or for the lowest temps and quietest operation. Don't buy bigger than your CPU needs.
Is 280mm better than 360mm? Often close in performance on quality units, and it fits more cases. If 280mm fits and 360mm doesn't, you're not giving up much. Both are sweet-spot-to-high-end choices.
The One Thing to Remember
AIO radiator size should match your CPU's heat output, not your ambition — 240mm is plenty for most mid-range and many high-end chips, while 360mm earns its place only for hot, high-core CPUs under sustained load. The performance gap is modest under light load and widens under heavy load. In Nigeria's heat, also weigh a robust, leak-free air cooler; match cooling to the CPU and don't overspend on radiator you won't use.
Choosing a cooler? Configure a build online → or talk to our team → and we'll match the cooling to your CPU's real heat and your case.