The DeepCool Assassin IV is the objective winner of this comparison, securing two out of three spec victories. Its most significant advantage is a 27% higher TDP rating compared to the alternative, indicating a superior capacity for handling thermal loads. While the DeepCool AK400 falls short in total spec wins, it maintains a distinct edge in affordability, offering an MSRP that is 70% better than the higher-tier model.

Choose the DeepCool Assassin IV if your primary requirement is maximum thermal management capability for high-performance systems. Conversely, the DeepCool AK400 is the logical selection for budget-conscious builders who prioritize cost efficiency over the increased TDP rating provided by the larger cooler. Your decision should depend on whether your specific build demands the enhanced thermal headroom of the former or the significant price advantage offered by the latter.