Both of the models are extreme slim with maximum height of 37mm, which makes both of them perfect solution for extreme slim cases. Apart from that the dimensions of the coolers are made so they provide full compatibility with all type of RAM modules and VGA cards on mini-ITX motherboards.
The NH-L9i and NH-L9a are premium quality quiet CPU coolers for Intel LGA115x (NH-L9i) and AMD FMx (NH-L9a) based HTPCs and Small Form Factor systems. Due to the slim 23mm heatsink and the NF-A9x14 low profile fan that measures only 14mm in thickness, the NH-L9 coolers stand a mere 37mm tall, which makes them ideal for use in compact HTPCs or Small Form Factor cases that offer minimum clearance for CPU coolers.
The heatsinks have a 95x95mm (NH-L9i) and 92x114mm (NH-L9a) footprint that complies exactly to the Intel LGA115x and AMD FMx socket keep-out zones. This means that the coolers are fully compatible with tall memory modules and PCIe cards on mini-ITX mainboards.
The highly optimised NF-A9x14 premium fan features Noctua’s proprietary AAO frame as well as sophisticated aerodynamic design measures. Supporting PWM for fully automatic speed control, the NF-A9x14 allows the NH-L9 coolers to stay remarkably quiet. The included Low-Noise Adaptor (L.N.A.) allows to reduce the maximum fan speed from 2500 to 1800rpm and makes it possible to create near-silent setups.