Air cooler or AIO liquid cooler? How to choose a CPU cooler
Tower coolers and all-in-one liquid coolers both cool well. What separates them is noise, fit, failure modes and price. How to pick, and the three measurements to check first.
Both kinds of cooler do the same job: move heat from the processor into the air inside your case, and from there out of it. Neither is automatically better. What separates them is how they fit, how they fail and how they sound.
Air coolers
A tower cooler is a stack of aluminium fins on copper heat pipes with one or two fans pushing air through it.
For: nothing to leak, no pump to wear out, cheaper for the same cooling at mid-range power levels, and they usually last as long as the PC does. The fan is the only moving part and it is a standard size you can replace.
Against: big towers are tall and heavy. They can block tall memory sticks and they need room in the case.
AIO liquid coolers
An all-in-one cooler pumps liquid from a block on the CPU to a radiator with fans on it, mounted on the case.
For: it moves the heat to the edge of the case, which helps with very hot processors and small cases. The area around the socket is clear, which suits tall memory and makes for a tidy build.
Against: the pump is a moving part that can fail, and when it does the CPU will overheat rather than slow down gracefully. They cost more, and the pump can make a faint noise that air coolers do not.
Three measurements to check first
1. Cooler height against case clearance (air). Every case states a maximum CPU cooler height, and every tower cooler states its own height. A cooler 2 mm too tall stops the side panel closing. Coolers on VantaSpec list their Height; take the case's figure from its manufacturer's specification page.
2. Radiator size against case mounts (AIO). Radiators come in 120, 240, 280 and 360 mm. The case has to have a mount for that size in the place you want it, and thick radiators plus fans can collide with motherboard heatsinks or memory at the top of the case.
3. Socket support. A cooler needs a mounting kit for your socket. AMD's AM4 and AM5 share a mounting pattern, as do Intel's LGA1700 and LGA1851, so most current coolers cover all four, but check the listed sockets before you buy.
How much cooling do you need?
A rough guide by processor:
- 65 W class chips (many Ryzen 5 and Core Ultra 5 models): a single-tower air cooler is plenty, and is often quieter than the cooler in the box.
- Mid-range 8-core chips: a good single tower or a 240 mm AIO.
- High-core-count chips that sustain 200 W or more: a large dual-tower cooler or a 360 mm AIO.
Be careful with cooler "TDP ratings". There is no shared standard for how a manufacturer measures them, so a 250 W rating from one brand is not comparable with a 250 W rating from another.
Mounting an AIO the right way
Air collects at the highest point of the loop. If that is the pump, it will rattle and cool badly. Mount the radiator on the top of the case, or on the front with the tubes at the bottom, so the radiator rather than the pump is the highest point.
The short version
Pick an air cooler unless you need the space around the socket, have a very hot processor, or are building in a case that favours a radiator. Then check height or radiator size, and socket, before price. Compare coolers.