Due to a decrease of the stack-up-height (height from the motherboard PCB to the top of the CPU heatspreader) from LGA115x/1200 to LGA1700/LGA1851, the NH-L9 cooler needed to be modified for the LGA1700/LGA1851 platform. To conform to all the required keep-in zones and ensure sufficient clearance for components underneath the cooler, the thickness of the baseplate had to be increased. Therefore, the NH-L9i is not compatible on LGA1700/LGA1851 as it would sit too low and may collide with components on the motherboard. At the same time, due to its thicker base, using the NH-L9i-17xx on an LGA115x/1200 CPU may cause irreversible damage as the mounting pressure is too high.