Will a Noctua NH-D15 G2 Fit in a Corsair 4000D? (2026)

Yes. A Noctua NH-D15 G2 fits in a Corsair 4000D. The cooler stands 168mm tall in its standard dual-fan configuration and the case clears 170mm, so you have 2mm of daylight.

That margin is also the catch. Noctua's fix for tall memory is to slide the front fan upward, and in a case with this little headroom every millimetre you lift the fan is a millimetre added to the cooler. Your memory will have to stay at or under 32mm, which means the buying decision here is really about low-profile DDR5, not the cooler.

At a glance

Verdict by scenario

Four situations cover almost every version of this question. Find yours and the answer is one row away.

How we measured the NH-D15 G2 fit in a Corsair 4000D

Two numbers decide the headline. Corsair lists 170mm of CPU cooler clearance for the original 4000D, the 4000D Airflow, and the current FRAME 4000D RS. Noctua lists 168mm for the NH-D15 G2 with both fans mounted in their standard positions. Subtract, and the answer is 2mm.

The third number is the one that bites. Noctua's own compatibility note says the NH-D15 G2 should be used with memory up to 32mm tall, or that the front fan can be raised in a chassis clearing more than 168mm. The 4000D clears that bar, so the raise is technically on the table. It just does not buy much. Every millimetre the fan goes up is a millimetre added to the cooler's overall height, and you have 2mm before the side panel becomes the problem. That gets you to roughly 34mm of memory, nowhere near the 40mm and up that most RGB kits run.

Single-fan mode is the real escape hatch. Pull the front fan off and the recessed lower fins open up at least 59mm of clearance, which covers any DDR5 kit sold today. You give back some of the thermal headroom the second fan was buying, and on a 9950X or a 14900K that trade is real rather than academic. On a mid-tier chip it barely registers. Our guide to choosing a CPU cooler walks through where that line sits.

The cooler in question: Noctua NH-D15 G2

Noctua NH-D15 G2, Quiet High-Performance Dual Tower CPU Cooler

$159.95

Buy the Noctua NH-D15 G2 on Amazon

Specs

What it does well

The G2 is the quiet answer. The two NF-A14x25r G2 fans ship with a deliberate speed offset between them, which keeps the pair from beating against each other at the RPMs you run. Under a normal gaming load it disappears into the room.

Mounting is the other reason people pay for it. The bracket holds the cooler square without a third hand, the offset base is designed around modern AM5 and LGA1851 hotspots, and the six year warranty is backed by support that answers. In a case with 2mm of margin, a mount that seats cleanly on the first try matters more than it does in a roomier build.

What you give up

Two millimetres, and the flexibility that usually comes with a Noctua tower. In a bigger chassis you would raise the front fan and forget about memory height. Here you cannot, so the cooler quietly writes a spec into the rest of your parts list.

The premium is also narrow. A gaming build where the owner wears headphones gets very little back from the noise floor, and thermally this sits in the same tier as towers costing a third as much. Buy it because you want quiet, not because you want temperatures.

Who it's for

The builder who has already decided that quiet is a requirement, is buying memory as part of the same order, and wants the cooler to be the last thermal decision in the build.

Low-profile DDR5 that clears the gate: Crucial Pro DDR5-6000 CL36

Crucial Pro 32GB DDR5 RAM Kit (2x16GB),CL36 6000MHz, Overclocking Desktop Gaming Memory, Intel XMP 3.0 & AMD Expo Compatible, Black - CP2K16G60C36U5B

$489.99

Buy the Crucial Pro DDR5-6000 CL36 on Amazon

Specs

What it does well

It clears the gate with the fan in its stock position. At 31.5mm the modules sit under the 32mm ceiling without single-fan mode, without lifting anything, and without the measuring tape moment when the cooler is already torqued down. If you want alternatives at the same height, our low-profile DDR5 roundup covers the rest of the field.

The speed grade is the one AM5 wants. DDR5-6000 at CL36 is the sensible operating point for Ryzen 7000 and 9000, and the kit carries both XMP 3.0 and EXPO profiles so the same sticks work if the build moves to an Intel board later.

What you give up

Looks. There is no RGB, no tall finned spreader, and no binning story. In a build with a glass side panel and a lighting plan, plain black memory next to a brown and beige cooler is a choice you have to be at peace with.

You also give up a little tuning headroom against the sharper binned kits. For a gaming rig that difference lands inside the margin of error; for a memory overclocker it does not.

Who it's for

Anyone pairing an NH-D15 G2 with a 4000D who wants clearance to stop being a variable, and anyone who would rather spend the difference on storage than on lit memory.

The tall-RAM alternative: Thermalright Phantom Spirit 120 EVO

Thermalright Phantom Spirit 120 EVO CPU Cooler,7×6mm Heat Pipes CPU Air Cooler,Dual PWM Fan Computer Cooling,2150RPM Speed,for AMD AM4 AM5/Intel 1700/1150/1151/1200/17XX/2011/1851

$46.90

Buy the Phantom Spirit 120 EVO on Amazon

Specs

What it does well

It solves the exact problem the G2 creates. At 157mm it leaves 13mm of headroom inside the 4000D, and it clears 42mm memory with the fan where the box put it, so an existing RGB kit stays in the build. Thermally it sits in the same conversation as the towers above it, which is why it keeps turning up in our air cooler picks.

The seven heatpipe stack and the twin 120mm fans handle a 9800X3D or a 14700K without drama. For most builders this is the cooler that ends the decision, and the money saved buys case fans or another drive.

What you give up

Noise floor and finish. At matched fan speeds the 120mm pair is audibly busier than Noctua's 140mm fans, the mounting hardware is fiddlier, and the warranty is shorter. Buyers have flagged that raising the front fan on twin-tower Thermalrights pushes total height past the spec sheet, so recheck the ceiling if you go that route.

Who it's for

The builder who already owns tall memory, or who would rather the cooler stopped being the expensive line item. If the RGB kit is non-negotiable and you also want the quiet, the honest third option is a taller case from our airflow mid-tower picks.

Bottom line

It fits. If your memory is 32mm or shorter, buy the NH-D15 G2 and stop reading. If you are buying memory anyway, get a 31.5mm kit and the question never comes up. If tall RGB modules are already installed, take the Phantom Spirit 120 EVO and spend the difference elsewhere. If none of those work, the case is the part to change, and our cooling and case framework covers what to look for.

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