No matter if you're building a custom desktop PC for all-out gaming or something more versatile, you'll need to keep the processor (CPU) cool under stress. Thermals spike up whenever you start up a demanding app or start playing a game, and some stock (included) CPU coolers won't always keep up with the demand. For that sake, I've always relied on two options, depending on my PC case of choice.
You see, a traditional air cooler like the Thermalright Peerless Assassin is simplistic but tall. The heatsink tower includes a collection of fins to dissipate heat, and can take up a sizeable amount of space above your CPU. On the other hand, an all-in-one (AIO) liquid cooler like ARCTIC's Liquid Freezer III PRO needs much less space around the CPU block, but demands space for a radiator (and its fans) somewhere else in your case.
I get it, it's daunting, but I've narrowed it down to only two picks to make it easier. Check your PC case and motherboard manuals for compatibility before committing to any component purchase, and plan your cable management ahead of time. After that, you can rest assured that either of these two picks will keep your CPU temperatures under control, as they always have for me.
September 8, 2025: ARCTIC replaced its Liquid Freezer III all-in-one CPU cooler with a 'Pro' model, which is inherently just as capable as its predecessor, with the only noticeable upgrades made to its included fans.
Which CPU cooler should you buy in 2025?
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I've used the Peerless Assassin 120 SE to cool both AMD (AM4/5) and Intel (LGA 1700/1851) chips without issue, and it remains inside a Ryzen 7800X3D rig. It's almost unfair how well it performs for its outrageously affordable price tag, and I haven't suffered any problems with it to date.
ARCTIC has updated its Liquid Freezer III AIO cooler since I used it, but still keeps it simple with its 'Pro' model available in 240mm, 280mm, 360mm, and even a monstrous 420mm variant. I'd prefer the Liquid Freezer III PRO 360 if it fits into my current case.
Thermalright for air cooling on a budget
Thermalright includes two 120mm fans with its Peerless Assassin air cooler alongside mounting brackets for Intel and AMD processors, with the appropriate standoffs for each. AM4 risers pair with a stock backplate on my motherboard to fit a compatible AM5 socket instead, and the whole thing barely takes fifteen minutes to complete once I connect the fan cable Y-splitter to its headers and clip on the fans. It's usually surfaced as an option for those on a strict budget, but the Peerless Assassin would happily fit into any mid-to-high-end custom build. It's just that good.
ARCTIC offers the best AIO coolers I've ever used
I've tested all-in-one (AIO) liquid coolers from the usual suspects, but I keep coming back to ARCTIC for its simplicity and performance. Now, the Liquid Freezer III features upgraded fans on its 360mm radiator (or whichever size you choose), which might be too big for some builds, and you should check your case compatibility before ordering.
Still, the original stood up to intensive benchmarking for plenty of modern AMD and Intel chips since its release, and there's plenty of positive feedback to suggest that nothing has changed in that category with its Pro model. Seeing its predecessor (Liquid Freezer II) or its standard clearance model (Liquid Freezer III) with a significant discount can be tempting, but the CPU block-mounted fan gives it enough of a unique edge to stand out, especially when a GPU is exhausting hot air toward your processor. It's still a winner.
CPU cooler compatibility: AMD vs. Intel
Choosing the proper cooler for your CPU depends on a few crucial factors. Compatibility is the name of the game, so you'll need to check your processor and the socket associated with it. For example, a 14th Gen Intel Core i7-14700K uses an LGA1700 socket like the 12th and 13th Gen before it. Thanks to cross-generation socket compatibility, pairing a cooler with Intel chips is a little easier, whereas AMD Ryzen processors are experiencing more of a generational shift from AM4 to AM5. Thankfully, AM4 coolers are generally identical to AM5 and often use the same brackets.
You should check the official Intel support page to identify Core desktop processors and, in the same way, the official AMD support page for Ryzen equivalents.
Once you're confident in compatibility, performance is the next priority. If you're building a custom gaming desktop with a power-hungry processor that draws around 120W TDP, you'll benefit from coolers like all-in-one (AIO) variants with larger 360mm radiators and triple-fan setups. Simply put, the more power a processor uses, the hotter it'll get. My top choice for the best AIO is the ARCTIC Liquid Freezer III specifically because it'll handle practically anything without getting too expensive. For those choosing more modest, power-conscious processors, the phenomenal Peerless Assassin 120 SE is an affordable marvel that handles thermal control without breaking the bank.
