The Noctua NH-U12S Redux is the objective winner of this comparison, securing two out of three spec victories. Its most significant advantage is a 79% higher TDP rating compared to the Noctua NH-L12S. While the Noctua NH-L12S offers a 5% improvement in noise level, the superior thermal handling capacity of the Noctua NH-U12S Redux makes it the more capable cooling solution overall based on the provided specifications.

Choose the Noctua NH-U12S Redux if your primary requirement is managing higher thermal loads, as its TDP rating provides a substantial performance advantage. Conversely, select the Noctua NH-L12S if your priority is minimizing acoustic output, as it offers a quieter operation. Your decision should depend on whether you value the increased thermal headroom of the former or the slight noise reduction provided by the latter.