The Arctic Liquid Freezer III 360 is the objective winner of this comparison, securing more total spec victories than its counterpart. Its most significant advantage is a 10% improvement in noise level, making it the quieter option for your system. While the Arctic Liquid Freezer III 420 offers a 17% larger radiator size, the 360 model maintains a superior balance across the measured specifications, providing a more refined acoustic profile for your cooling needs.

Choose the Arctic Liquid Freezer III 360 if you prioritize a quieter operating environment and a more versatile fit for your chassis. Conversely, select the Arctic Liquid Freezer III 420 if your primary requirement is the increased radiator surface area provided by its larger design. Both units offer distinct benefits, so your decision should depend on whether you value the reduced noise output of the 360 or the physical dimensions of the 420.