Noctua’s DX line CPU coolers have become a default choice in premium grade quiet cooling solutions for Intel Xeon processors. The NH-D9 DX-4677 4U features a larger, custom-designed contact surface for LGA4677 platforms. Based on the proven, 92mm size NH-D9L heatsink and equipped with two of Noctua’s award-winning, PWM controlled NF-A9 92mm fans (high-efficiency 2500rpm version), it combines strong performance with excellent compatibility for 4U systems and other space-restricted applications. The NH-U9’s direction of airflow is perpendicular to the long axis of the LGA4677 socket, so it is ideal for systems where the exhaust fans of the chassis are in this direction. For systems that require the airflow to go parallel to the long axis of the socket, please choose the NH-D9 DX-4677 4U. Topped off with the professional SecuFirm2™ mounting system and pre-applied NT-H1 thermal compound, the NH-D9 DX-4677 4U forms a complete premium quality package for quietly cooling LGA4677 based Xeon workstations and servers.