Hi, I'm currently using a Noctua NH-U12S without any problems with no covered slots (at standard cpu frequency the average idle temperature is 23 °C and under load has never reached 50°C). However I think that with the bigger NH-D14 you seriously risk that at least a slot will be covered (it depends on how you mount the cooler as well of course). Maybe you can check and see on the nooctua website for precise indications of the dimensions of the cooler. All the best.