After Noctua tested “more than a hundred cases,” it found that 56 had a significant discrepancy between the actual CPU cooler clearance and the one listed by the case manufacturer. But the more troubling finding is cases that show a larger figure for clearance than actually exists, which could result in wholly incompatible builds. In cases from Asus and Lian-Li, Noctua found real clearances that were 1.8mm and 3.5mm shorter than the specs listed by their manufacturers, respectively. That makes those cases incompatible with specific CPU coolers in Noctua’s catalog that should otherwise fit according to the manufacturer’s guidelines. After seeing nearly half of these values deviate from their official specs, I think I’ll start taking my own measurements whenever I need a new CPU cooler.