Should I use an air cooler or an AIO for a Ryzen 5 5600X?

I ran a 5600X with an AIO and later switched to a large dual-tower air cooler. The temperatures were only about 3°C different, even under load. A single-tower cooler should be perfectly fine unless you specifically want lower fan speeds or the look of liquid cooling.

An AIO would mainly be for appearance or personal preference here, not performance. Air coolers are cheaper, simpler, and generally last longer since there’s no pump that can fail or coolant that can leak. A Peerless Assassin or another dual-tower cooler is more than enough, though it’s arguably overkill for a 5600X.

Stick with air cooling. The 5600X is a 65W CPU and doesn’t need much cooling; a basic single-tower cooler such as a DeepCool AG400 or similar will handle it easily.

You could also compare the regular Ryzen 5 5600 or the Ryzen 7 5700X if they’re priced better. The difference between the 5600 and 5600X is fairly small, and neither one requires an AIO.