The CPU cooler shortlist

The best CPU cooler for most gaming PCs in the UK is the Thermalright Peerless Assassin 120 SE, at £26.90 on Amazon UK at the time of writing (October 2026): a dual-tower air cooler that Tom's Hardware names the best air cooler for most people. Hotter chips such as the 250 W Intel Core Ultra 7 270K Plus justify the ARCTIC Liquid Freezer III Pro 360 at £67.49. The longer comparison is in Is an AIO better than an air cooler?

What is a CPU fan, and do you need a CPU cooler?

A CPU fan moves air through a heatsink or radiator so the processor's heat leaves the case, and every PC needs a cooler. Intel K-series chips and AMD X3D chips are sold without one, so the cooler is a separate purchase. A tower cooler uses heat pipes to carry heat to its fins, and an AIO uses liquid to carry it to a radiator.

The CPU fan is also the loudest part of a cooler. Noctua rates each 140 mm fan on the NH-D15 G2 at 24.8 dB(A) at its 1,500 rpm maximum, while Tom's Hardware measured the ARCTIC Liquid Freezer III Pro at 52.6 dBA at full fan speed. Case fans share the load; see How many case fans do I need?

How much cooler does each CPU need?

A CPU turns every watt it draws into a watt of heat, so the cooler class should follow the chip's rated power. A 250 W Intel chip produces 3.8 times the heat of a 65 W Ryzen 5. Tom's Hardware says the Peerless Assassin cooled a Core i9-12900K drawing over 200 W better than rival air coolers, which is the clearest published evidence of its headroom.

Tom's Hardware measured the ARCTIC Liquid Freezer III Pro cooler than the air coolers in its chart with a Ryzen 9 9950X3D held at 150 W and a 290 W graphics load. The processors themselves are ranked in Best CPU for gaming UK 2026.

Which CPU cooler should you buy?

1. Thermalright Peerless Assassin 120 SE: best for most

The Thermalright Peerless Assassin 120 SE costs £26.90 and cools anything up to a 120 W Ryzen 7 9800X3D with no pump to fail. It has six heat pipes, two 120 mm fans at up to 1550 rpm and a 155 mm height.

2. ARCTIC Liquid Freezer III Pro 360: best AIO

The ARCTIC Liquid Freezer III Pro 360 is the AIO to buy, at £67.49. Tom's Hardware names it the best 360 mm AIO, and ARCTIC backs it for 6 years. The radiator is 38 mm thick, and ARCTIC says the cooler needs 63 mm with its fans.

3. Noctua NH-D15 G2: best premium air cooler

The Noctua NH-D15 G2 costs £127.95 and suits buyers who want air-cooling reliability with the lowest noise. It has eight heat pipes, two 140 mm fans rated at 24.8 dB(A) and a 6-year warranty.

4. Thermalright Assassin X 120 Refined SE: best budget

The Thermalright Assassin X 120 Refined SE costs £15.19, the lowest price here. Thermalright lists four 6 mm heat pipes, one 120 mm fan at up to 1550 rpm and 25.6 dB(A), and a 148 mm height.

Will a CPU cooler fit your case?

The Thermalright Assassin X 120 Refined SE (148 mm) and the Thermalright Peerless Assassin 120 SE (155 mm) each fit four of the five cases below, and the Noctua NH-D15 G2 (168 mm) fits two. Each limit is the case maker's published figure.

Spare millimetres matter because a cooler pressed against a side panel loses airflow. The Phanteks XT Pro Ultra leaves 36 mm spare with the Assassin X 120 Refined SE and 16 mm with the Noctua NH-D15 G2, while the NZXT H5 Flow leaves 2 mm with the Noctua.

The Fractal Design North shows the exception: at 145 mm it rules out all three towers. A 360 mm AIO also needs depth, since the ARCTIC Liquid Freezer III Pro 360 needs 63 mm and NZXT allows a 30 mm radiator on the H6 Flow's roof, which suits the 27 mm MSI MAG CORELIQUID A13 360.

Which CPU sockets do these coolers support?

All four picks list AM4, AM5, LGA1700 and LGA1851 mounts, so each fits current AMD and Intel desktop boards. The Thermalright Assassin X 120 Refined SE adds older Intel sockets, LGA1200 and LGA115X, in its listing. The ARCTIC Liquid Freezer III Pro 360 uses a contact frame on Intel boards, which ships in the box. Buyers pairing a cooler with a processor can check the chip's socket in Best CPU for gaming UK 2026.

Thermal paste comes pre-applied on some coolers and in a syringe on others, so buyers replacing a cooler should keep the old tube unless the new one includes paste. Tower coolers also hang over the top RAM slot on some boards, which makes the height of the memory modules worth checking. Lower-profile kits avoid the clash.

What does the extra money buy in a CPU cooler?

Each step up the ladder buys cooling headroom, quiet or warranty, not frame rates. The Noctua NH-D15 G2 costs 4.8 times the Peerless Assassin 120 SE, and the ARCTIC Liquid Freezer III Pro 360 costs 2.5 times as much.

The ARCTIC is the cheapest cover per warranty year among the AIOs with a stated warranty, at £11.25. The Corsair and NZXT ranges are compared in Best Corsair products UK 2026 and Best NZXT products UK 2026.

Who should skip a new CPU cooler?

Buyers of CPUs sold with a boxed cooler, and anyone running a 65 W chip in a quiet office PC, can keep the boxed cooler. Buyers of small-form-factor cases should check the 70 mm limit on the Cooler Master NR200P V3 before any tower. Buyers who move their PC often should weigh the 1,525 g of the Noctua NH-D15 G2.

Verdict

The Thermalright Peerless Assassin 120 SE at £26.90 is the best CPU cooler for most gaming PCs. The ARCTIC Liquid Freezer III Pro 360 at £67.49 is the one to buy for 250 W chips, and the Thermalright Assassin X 120 Refined SE at £15.19 is the budget answer. Pair them with a processor from Best CPU for gaming UK 2026.