Thermalright Peerless Assassin 120 SE

Dual-tower air cooler. Six 6mm AGHP heatpipes, nickel-plated copper base.

Two 120mm TL-C12C PWM fans, 1550 RPM, 66.17 CFM, rated 25.6 dB(A) maximum.

Dimensions 125 x 135 x 155mm. Weight about 1.3kg with both fans fitted.

Sockets: AM4, AM5, LGA1700, LGA1851, LGA1150/1151/1155/1200.

Lighting: none. Bare aluminium fins with two black top covers supplied.

Heatsink, two fans with wire clips, Intel backplate and standoffs, AMD mounting bars, a long screwdriver, a small tube of paste and the two black top covers.

Nothing is missing and nothing extra needs buying. The bundled paste is adequate for a first build. We would still use a proper tube if you already own one, because the supplied syringe is barely enough for one mount and you will want a second go at it.

This is a bare metal cooler and it looks it. No shroud, no logo plate, no lighting. The fins are aluminium, the base is nickel-plated copper, and the finish is flat enough that you can skip lapping.

The front tower sits high to clear memory, and the outer fan hangs off the side on wire clips so you can raise it. The two black top covers clip over the fin stacks and hide the heatpipe ends, which is the only concession to looks in the whole package.

Thermalright claims 245W of dissipation. Independent testing lands close.

Tom's Hardware measured 61C over ambient at a 200W load on a Core i9-12900K. That puts it within a few degrees of dual-tower coolers at three times the price and comfortably ahead of every single-tower 120mm cooler we have seen tested.

One warning. The famous Gamers Nexus charts everybody quotes are for the original PA120, not the SE. The SE uses different fans. The gap is small but the numbers are not interchangeable, and plenty of retail listings blur the two.

There is no single Peerless Assassin 120.

Thermalright ships the SE, the V2, the V3, the Extrem, an ARGB version and a White version. They share the heatsink but differ in fans, RPM and sometimes base finish. The V2 runs 1850 RPM fans and is measurably louder.

Reviews rarely say which one they tested. Retail listings rarely say which one they are selling. If you are buying on the strength of a review, match the exact suffix on the box or you are buying a different cooler.

Installation is genuinely easy. Backplate, four standoffs, mounting bars, then two captive spring screws through the middle of the heatsink. The supplied screwdriver reaches between the towers so you do not have to remove the front fan.

RAM clearance is the annoying part. Thermalright publishes no official figure. The 45mm number quoted everywhere has no primary source we can find. In practice low-profile kits fit fine and tall RGB kits force the front fan upward, which then fouls the side panel on slim cases.

At idle and light load this cooler is inaudible in a closed case.

Push it past 180W and the fans ramp to 1550 RPM, and you hear them. Not a whine, just broad airflow noise, but it is clearly present. Setting a flatter curve costs about 3C and fixes it.

The second limitation is height. At 155mm it does not fit most mATX and SFF cases. Check your case spec before ordering, because the box does not come back cheaply.

Thermalright states 3 to 6 years depending on region and listing. We have seen both printed on current retail boxes.

Assume 3 years unless your specific seller confirms otherwise, and keep the invoice. Arctic covers its coolers for 6 years without the ambiguity, which matters if warranty terms are part of your decision.

The heatsink itself has no failure mode. If anything dies it is a fan bearing, and replacement TL-C12C fans cost about $8.

Winner at this price: the Thermalright Phantom Spirit 120 SE, not this cooler. It is the same money, from the same company, with seven heatpipes instead of six, and it tests a couple of degrees cooler.

Against the Cooler Master Hyper 212 Halo at around $45, the Peerless Assassin wins on cooling and loses on looks.

Against a $100 360mm AIO such as the Arctic Liquid Freezer III, the AIO wins above 250W. Below that the gap is smaller than the price difference suggests.

Currently $32.31, which is below its launch price. Stock is steady on Amazon and Newegg.

At this money there is no reason to buy a single-tower cooler for a mainstream build. The only real decision is whether to spend the same amount on the Phantom Spirit instead.

If you see it listed above $45, wait. It drops back within a week or two, and the price has never held high for long.

Will it fit my case? You need 160mm of CPU cooler clearance to be safe. 155mm is the cooler, and the fan clips sit slightly proud.

Will it clear my RAM? Low-profile kits yes. Tall kits mean raising the front fan, which adds about 10mm to total height.

Does it support LGA1851? Yes, current boxes include the bracket. Older stock may need a free bracket request from Thermalright.

Can it handle a 14900K? For gaming and normal work, yes. For sustained all-core renders at 250W and up, no. Nothing air-cooled is comfortable there.

Can it handle a 9800X3D or 9950X? Comfortably. AM5 chips cap around 160W to 200W.

Is it quieter than a 360mm AIO? At low load yes, because there is no pump. At full load no.

Which version should I buy? The plain SE for most builds. The ARGB version if you want lighting and will pay about $12 more. Skip the V2 unless you want the higher RPM fans.

Do I need to buy paste? No, a tube is included.

Is the White version the same cooler? Same heatsink, white fans, usually $6 to $8 more. Performance is identical.