"The NH-L12 manages to keep quite close to the heavier and more efficient NH-U12P. The difference between them in idle temperatures is almost neglible while the room temperature in the testing environment was around 25c. In the ultimate stress test the difference is about 4 degrees which is still quite a good performance this low profile cooler."
Ville Ilonen - RBmods
Gosh..... That's totally kickass!
Noctua NH-L12 Low Profile CPU cooler review by RBmods - Introduction & Conclusion.