Noctua NH-D9L

Noctua rates the NH-D9L for up to 180W, respectable for a cooler this short, and the dual-tower layout with a single 92mm NF-A9 fan gives it more surface area to work with than most single-tower compacts at the same height. It's not chasing flagship numbers, it's chasing the best thermal performance Noctua could fit into 110mm.

The single NF-A9 92mm fan runs at 23.6dBA, quiet enough that most builders won't notice it under normal load, and Noctua's usual SSO2 bearing keeps long-term reliability high. There's no second fan mount here, so what you see is what you get, unlike the larger NH-D9L's siblings that support push-pull.

AM4/AM5 and LGA1700/1200 are covered with Noctua's SecuFirm2 mounting system, the same reliable hardware used across the rest of the lineup, so installation in a cramped mATX case is as straightforward as on any full tower.

The dual-tower fin stack keeps Noctua's brown-and-tan colorway and copper heatpipe construction, just compressed to 110mm tall, and the narrow single-fan width means RAM clearance is generally good even with taller heat-spreader memory.

Against Noctua's own NH-U9S, covered elsewhere on this site, the NH-D9L's dual-tower design gives it a real thermal edge at a similar height, so we'd pick the D9L first unless the U9S's slightly narrower single-tower footprint is specifically needed. Against DeepCool's AK400, also on this site, the D9L costs more but runs quieter and with Noctua's mounting and long-term reliability track record, which matters more in a small case you won't be reopening often.