GoKawiilWhy it matters: Have you ever bought a CPU cooler and found it doesn't fit in your case, despite having first checked to ensure compatibility? Noctua says this can be a problem because many PC cases' actual measurements don't line up with manufacturers' official specs.
Noctua writes that, given the importance of every millimeter in small-form-factor and ITX builds, it has conducted its own measurement tests on popular cases to confirm they align with figures on the manufacturers' websites. It found inaccuracies in 56 out of the more than 100 cases it tested.
One recent example of a significant deviation was the new NZXT H2 Flow. The maker says the case offers up to 75mm of CPU cooler clearance, but Noctua found enough space to fit coolers up to 79mm. That means the company's NH-L12Sx77 cooler actually fits this case despite the specs suggesting it won't.
Another example was the Thermaltake TR100 case. It specifies 68mm of clearance, but it can fit coolers up to 70.7mm in height. Other cases also offered more space than specified, including Corsair's popular 5000D, 4000D, and Frame 4000D.
While missing out on a preferred cooler when it could have fit is frustrating, buying one that's too large is a lot worse. Noctua found several cases where there was less clearance room than the manufacturer specified.
The Asus Prime AP201, for example, has 168.3mm instead of the claimed 170mm. There was also the Lian Li B4-mATX, which has 164.5mm of clearance instead of the specified 168mm.
Having less room than expected could lead to a multitude of problems. The cooler could be pressed against the case panels. Or, as Noctua notes, there might be no room to move a front fan higher up to increase RAM clearance. Worst of all, the case might not close at all if there's a significant difference between the stated and actual heights.
To help buyers of its coolers, Noctua has added a new custom field to its case compatibility database. Any time a small tooltip icon appears next to the maximum CPU cooler height specification of a particular case model, it means the company's own measurements deviate from the manufacturer's specifications. With more than 56% of case measurements being inaccurate, this could save PC builders a lot of headaches.