Noctua nh-d15s

The NH-D15S only comes with one 140mm fan, but does come with the spring clips to mount an extra if you want - so you could add a 120mm fan in front, which provides much more RAM clearance. It also has the heatsinks offset from the centerline of the CPU, away from the PCIe slot - so the NH-D15S actually fits some motherboard where the PCIe x16 slot is in the highest position, when the NH-D15 won't.

The NH-D15S will fit, but I think you’ll probably have issues with the NH-D15 given the front fan-RAM clearance, and maybe PCIe slit clearance depending on the motherboard.

Once I realized it I upgraded to a Noctua nh-d15s. The S is a special variant that focuses on better fitment (to clear the RAM). Thermal throttling went away instantly and it never gets above 70-75C now.

Cooler: Noctua NH-D15S

The rest of the build (or what is important for this question ) is an I7 12700k (not overclocked) cooled by Noctua NH-D15s recently re-pasted, on an MSI Z690 Pro board and everything is enclosed in Corsair 275R airflow case.

Hopefully assuming you're getting the current version of the D15S and that the box contents still match the instructions i'm looking at, ... Once you've got those bracket pieces on, you then need a little blob of thermal paste squeezed onto the CPU, then can put the cooler on, the base of the cooler has two spring loaded screws, those line up with the studs on the bracket and push + screw on, can take a bit of force to get them started, once you've got the first screw with one or two turns down get the other one on, do that a couple turns in, then go back to tighten first one all the way then second.