Noctua D-Type Tower Cooler_ Retail Cooling NH-D9DX i4 3U The NH-D9DX i4 stands only 110mm tall. This is 15mm less than previous 4U compliant 9cm DX-line coolers and allows the NH-D9DX i4 to also fit 3U cases - ideal for noise-sensitive 3U applications in fields such as audio or video processing! With its 95x95mm footprint, the NH-D9DX i4 does not overhang the RAM slots on LGA2011 Square ILM, LGA1366 and LGA1356. This gives the user full access to the memory modules and guarantees 100% compatibility with tall heat spreaders or optional memory fans. The NF-A9 92mm fan supplied with the NH-D9DX i4 supports PWM for convenient automatic speed control through the mainboard. And, the maximum fan speed can be reduced from 2000 to 1550rpm using the supplied Low-Noise Adaptor for even quieter operation The NH-D9DX i4 includes an extra set of fan mounting clips for users who want to achieve even better cooling performance by adding a second, optional NF-A9 to the front fin stack. Using the y-cable supplied with the NF-A9 PWM retail fan, both fans can be connected to one CPU fan header.