First, read the specifications carefully to determine which sink size or radiator size would be best. Manufacturers often specify the height of their cooler or the size of the radiator. You also need to make sure that the coolant you are going to buy allows enough space to clear over the motherboard to get your memory and adequate clearance under the RAM heat spreader. Although in liquid cooling, an important factor in determining the suitability will be the number of radiators and how large the radiators can be. This is not a problem either as manufacturers specify the location of the radiators and their size. Some radiators are installed at the top, which can be a problem as it may interfere with your motherboard.