Whether you’re after higher sustained clock speeds with your shiny Core i9-13900K, or you just a system that remains quiet under load, there are a few key things to consider when choosing the best AIO (all-in-one) cooler for your new build or an upgrade. AIO coolers are far more convenient and affordable than custom liquid cooling loops, and they can generally deliver lower CPU temperatures with less fan noise than air coolers–although that’s not always the case.

You’ll need to make sure there’s room to install an AIO cooler in your case as well, preferably in the top or rear, exhausting your CPU heat out of the case. AIO coolers typically come in three sizes, defined by the dimensions of the radiator and the fans the radiator is designed to fit: 120 (one 120mm fan), 240 (two 120mm fans), or 360mm (three 120mm fans). There are some 140 and 280mm AIO coolers as well, but they are far less common. As you might suspect, the larger the radiator, generally, the greater the cooling potential, although things like radiator thickness, materials, and fan and pump performance factor into cooling capability as well. 

If you aren’t running a flagship CPU with lots of cores and 5-6 GHz speeds and you don’t plan on overclocking, a 120mm AIO, which you can usually mount in the rear exhaust fan area of your PC case, should suffice. That said, Intel’s 12th and 13th Gen CPUs are generally more demanding on coolers. And AMD’s Ryzen 7000, while less thermally demanding than Intel’s chips, isn’t exactly easy to cool either. So if you want better temperatures and slower-spinning fans, a good 240mm AIO cooler is a better choice, but won’t fit in as many cases. Generally, a 360mm AIO is your best bet for high-end, overclocked CPUs, to make sure your processor stays reasonably cool while running above its specced speed. But of course, those larger coolers fit in even fewer cases. Be sure to check your system or PC case manual to make sure your AIO cooler of choice will fit before buying.